MCC, a new interacting protein for Scrib, is required for cell migration in epithelial cells

To further characterize the molecular events supporting the tumor suppressor activity of Scrib in mammals, we aim to identify new binding partners. We isolated MCC, a recently identified binding partner for β-catenin, as a new interacting protein for Scrib. MCC interacts with both Scrib and the NHERF1/NHERF2/Ezrin complex in a PDZ-dependent manner. In T47D cells, MCC and Scrib proteins colocalize at the cell membrane and reduced expression of MCC results in impaired cell migration. By contrast to Scrib, MCC inhibits cell directed migration independently of Rac1, Cdc42 and PAK activation. Altogether, these results identify MCC as a potential scaffold protein regulating cell movement and able to bind Scrib, β-catenin and NHERF1/2.

Structured summary

MINT-7211022: SCRIB (uniprotkb:Q14160) and MCC (uniprotkb:P23508) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7210609: SCRIB (uniprotkb:Q14160) physically interacts (MI:0915) with MCC (uniprotkb:P23508) by two hybrid (MI:0018)MINT-7210759, MINT-7210792: SCRIB (uniprotkb:Q14160) physically interacts (MI:0914) with PIX beta (uniprotkb:Q14155) by pull down (MI:0096)MINT-7210883, MINT-7210820: SCRIB (uniprotkb:Q14160) physically interacts (MI:0914) with MCC (uniprotkb:P23508) by anti bait coimmunoprecipitation (MI:0006)MINT-7210634, MINT-7210690, MINT-7210731: SCRIB (uniprotkb:Q14160) physically interacts (MI:0914) with MCC (uniprotkb:P23508) by pull down (MI:0096)MINT-7211267: E6 (uniprotkb:P06463) physically interacts (MI:0915) with SCRIB (uniprotkb:Q14160), SNX27 (uniprotkb:Q96L92), UTRN (uniprotkb:P46939), CASK (uniprotkb:O14936), DMD (uniprotkb:P11532) and Dlg (uniprotkb:Q12959) by pull down (MI:0096)MINT-7211237: MCC (uniprotkb:P23508) physically interacts (MI:0915) with SCRIB (uniprotkb:Q14160), EZR (uniprotkb:P15311), SNX27 (uniprotkb:Q96L92), NHERF1 (uniprotkb:O14745) and NHERF2 (uniprotkb:Q15599) by pull down (MI:0096)     

Interactions with LC3 and polyubiquitin chains link nbr1 to autophagic protein turnover

Nbr1, a ubiquitous kinase scaffold protein, contains a PB1, and a ubiquitin-associated (UBA) domain. We show here that the nbr1 UBA domain binds to lysine-48 and -63 linked polyubiquitin-B chains. Nbr1 also binds to the autophagic effector protein LC3-A via a novel binding site. Ubiquitin-binding, but not PB1-mediated p62/SQSTM1 interaction, is required to target nbr1 to LC3 and polyubiquitin-positive bodies. Nbr1 binds additionally to proteins implicated in ubiquitin-mediated protein turnover and vesicle trafficking: ubiquitin-specific peptidases USP8, and the endosomal transport regulator p14/Robld3. Nbr1 thus contributes to specific steps in protein turnover regulation disrupted in several hereditary human diseases.

Structured summary

MINT-7034452: USP8 (uniprotkb:P40818) physically interacts (MI:0218) with NBR1 (uniprotkb:Q14596) by pull down (MI:0096)MINT-7034438: SQSTM1 (uniprotkb:Q13501) and LC3 (uniprotkb:Q9H492) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7034309: NBR1 (uniprotkb:Q14596) physically interacts (MI:0218) with Ubiquitin (uniprotkb:P62988) by pull down (MI:0096)MINT-7034323: NBR1 (uniprotkb:P97432) physically interacts (MI:0218) with Ubiquitin (uniprotkb:P62988) by pull down (MI:0096)MINT-7034233: NBR1 (uniprotkb:Q14596) physically interacts (MI:0218) with USP8 (uniprotkb:P40818) by two hybrid (MI:0018)MINT-7034207: NBR1 (uniprotkb:Q14596) physically interacts (MI:0218) with Robld3 (uniprotkb:Q9JHS3) by two hybrid (MI:0018)MINT-7034400, MINT-7034418: NBR1 (uniprotkb:Q14596) and LC3 (uniprotkb:Q9H492) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7034167: NBR1 (uniprotkb:Q14596) physically interacts (MI:0218) with Ubiquitin B (uniprotkb:Q78XY9) by two hybrid (MI:0018)MINT-7034470: NBR1 (uniprotkb:Q14596) and USP8 (uniprotkb:P40818) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7034194: NBR1 (uniprotkb:Q14596) physically interacts (MI:0218) with LC3-A (uniprotkb:Q91VR7) by two hybrid (MI:0018)MINT-7034336: SQSTM1 (uniprotkb:Q13501) physically interacts (MI:0218) with Ubiquitin (uniprotkb:P62988) by pull down (MI:0096)MINT-7034375: NBR1 (uniprotkb:Q14596) physically interacts (MI:0218) with LC3 (uniprotkb:Q9H492) by pull down (MI:0096)MINT-7034350: NBR1 (uniprotkb:Q14596) and Ubiquitin (uniprotkb:P62988) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7034181: NBR1 (uniprotkb:Q14596) physically interacts (MI:0218) with Tmed10 (uniprotkb:Q9D1D4) by two hybrid (MI:0018)MINT-7034220: NBR1 (uniprotkb:Q14596) physically interacts (MI:0218) with ube2o (uniprotkb:Q6ZPJ3) by two hybrid (MI:0018)     

Identification of LRP1B-interacting proteins and inhibition of protein kinase Cα-phosphorylation of LRP1B by association with PICK1

Recent studies show LDL receptor-related protein 1B, LRP1B as a transducer of extracellular signals. Here, we identify six interacting partners of the LRP1B cytoplasmic region by yeast two-hybrid screen and confirmed their in vivo binding by immunoprecipitation. One of the partners, PICK1 recognizes the C-terminus of LRP1B and LRP1. The cytoplasmic domains of LRP1B are phosphorylated by PKCα about 100 times more efficiently than LRP1. Binding of PICK1 inhibits phosphorylation of LRP1B, but does not affect LRP1 phosphorylation.This study presents the possibility that LRP1B participates in signal transduction which PICK1 may regulate by inhibiting PKCα phosphorylation of LRP1B.

Structured summary

MINT-6801075: Lrp1b (uniprotkb:Q9JI18) physically interacts (MI:0218) with SNTG2 (uniprotkb:Q925E0) by two hybrid (MI:0018)MINT-6801030, MINT-6801468: Lrp1b (uniprotkb:Q9JI18) physically interacts (MI:0218) with Pick1 (uniprotkb:Q80VC8) by two hybrid (MI:0018)MINT-6801284: LRP1B4 (uniprotkb:Q9JI18) physically interacts (MI:0218) with RanBPM (uniprotkb:P69566) by anti tag coimmunoprecipitation (MI:0007)MINT-6801108: Lrp1b (uniprotkb:Q9JI18) physically interacts (MI:0218) with Grb7 (uniprotkb:Q03160) by two hybrid (MI:0018)MINT-6801090: Lrp1b (uniprotkb:Q9JI18) physically interacts (MI:0218) with RanBPM (uniprotkb:P69566) by two hybrid (MI:0018)MINT-6801008: Lrp1b (uniprotkb:Q9JI18) physically interacts (MI:0218) with Jip-1b (uniprotkb:Q9WVI9-1) by two hybrid (MI:0018)MINT-6801052: Lrp1b (uniprotkb:Q9JI18) physically interacts (MI:0218) with Jip-2 (uniprotkb:Q9ERE9) by two hybrid (MI:0018)MINT-6801258, MINT-6801271: LRP1B4 (uniprotkb:Q9JI18) physically interacts (MI:0218) with Pick1 (uniprotkb:Q80VC8) by anti tag coimmunoprecipitation (MI:0007)MINT-6801244: RanBPM (uniprotkb:P69566) physically interacts (MI:0218) with mLRP4 (uniprotkb:Q8VI56) by anti tag coimmunoprecipitation (MI:0007)MINT-6801131, MINT-6801158: LRP1B4 (uniprotkb:Q9JI18) physically interacts (MI:0218) with Jip-1b (uniprotkb:Q9WVI9-1) by anti tag coimmunoprecipitation (MI:0007)MINT-6801231: PICK1 (uniprotkb:Q80VC8) physically interacts (MI:0218) with mLRP4 (uniprotkb:Q8VI56) by anti tag coimmunoprecipitation (MI:0007)MINT-6801173: Jip-1b (uniprotkb:Q9WVI9-1) physically interacts (MI:0218) with mLRP4 (uniprotkb:Q8VI56) by anti tag coimmunoprecipitation (MI:0007)     

Oligomeric structure of LOV domains in Arabidopsis phototropin

Oligomeric structures of the four LOV domains in Arabidopsis phototropin1 (phot1) and 2 (phot2) were studied using crosslinking. Both LOV1 domains of phot1 and phot2 form a dimer independently on the light conditions, suggesting that the LOV1 domain can be a stable dimerization site of phot in vivo. In contrast, phot1-LOV2 is in a monomer-dimer equilibrium and phot2-LOV2 exists as a monomer in the dark. Blue light-induced a slight increase in the monomer population in phot1-LOV2, suggesting a possible blue light-inducible dissociation of dimers. Furthermore, blue light caused a band shift of the phot2-LOV2 monomer. CD spectra revealed the unfolding of helices and the formation of strand structures. Both light-induced changes were reversible in the dark.

Structured summary

MINT-6823377, MINT-6823391:PHOT1 (uniprotkb:O48963) and PHOT1 (uniprotkb: O48963) bind (MI:0407) by cross-linking studies (MI:0030)MINT-6823495, MINT-6823508:PHOT2 (uniprotkb:P93025) and PHOT2 (uniprotkb:P93025) bind (MI:0407) by cross-linking studies (MI:0030)     

Molecular determinants of the interactions between SRC-1 and LXR/RXR heterodimers

Liver X receptor (LXR)/retinoid X receptor (RXR) heterodimers have been shown to perform critical functions in cholesterol and lipid metabolism. Here, we have conducted a comparative analysis of the contributions of LXR and RXR binding to steroid receptor coactivator-1 (SRC-1), which contains three copies of the NR box. We demonstrated that the coactivator-binding surface of LXR, but not that of RXR, is critically important for physical and functional interactions with SRC-1, thereby confirming that RXR functions as an allosteric activator of SRC-1-LXR interaction. Notably, we identified NR box-2 and -3 as the essential binding targets for the SRC-1-induced stimulation of LXR transactivity, and observed the competitive in vitro binding of NR box-2 and -3 to LXR.

Structured summary

MINT-7986678, MINT-7986639, MINT-7986700, MINT-7986720, MINT-7986736, MINT-7986760, MINT-7986787: LXR (uniprotkb:Q13133) physically interacts (MI:0915) with SRC1 (uniprotkb:Q15788) and RXR (uniprotkb:P19793) by pull down (MI:0096)MINT-7986596, MINT-7986621: SRC1 (uniprotkb:Q15788) physically interacts (MI:0915) with LXR (uniprotkb:Q13133) by pull down (MI:0096)MINT-7986555, MINT-7986575: LXR (uniprotkb:Q13133) physically interacts (MI:0915) with SRC1 (uniprotkb:Q15788) by two hybrid (MI:0018)MINT-7986808, MINT-7986907, MINT-7986890: SRC1 (uniprotkb:Q15788) binds (MI:0407) to LXR (uniprotkb:Q13133) by pull down (MI:0096)MINT-7986822, MINT-7986848, MINT-7986865: SRC1 (uniprotkb:Q15788) binds (MI:0407) to RXR (uniprotkb:P19793) by pull down (MI:0096)     

Comparing system-specific chaperone interactions with their Tat dependent redox enzyme substrates

Redox enzyme substrates of the twin-arginine translocation (Tat) system contain a RR-motif in their leader peptide and require the assistance of chaperones, redox enzyme maturation proteins (REMPs). Here various regions of the RR-containing oxidoreductase subunit (leader peptide, full preprotein with and without a leader cleavage site, mature protein) were assayed for interaction with their REMPs. All REMPs bound their preprotein substrates independent of the cleavage site. Some showed binding to either the leader or mature region, whereas in one case only the preprotein bound its REMP. The absence of Tat also influenced the amount of chaperone-substrate interaction.

Structured summary

MINT-8047497: FdhE (uniprotkb:P13024) and FdoG (uniprotkb:P32176) physically interact (MI:0915) by two hybrid (MI:0018)MINT-8046441: HybO (uniprotkb:P69741) and HybE (uniprotkb:P0AAN1) physically interact (MI:0915) by two hybrid (MI:0018)MINT-8046375: DmsA (uniprotkb:P18775) and DmsD (uniprotkb:P69853) physically interact (MI:0915) by two hybrid (MI:0018)MINT-8046425: TorA (uniprotkb:P33225) and TorD (uniprotkb:P36662) physically interact (MI:0915) by two hybrid (MI:0018)MINT-8046393: NarJ (uniprotkb:P0AF26) and NarG (uniprotkb:P09152) physically interact (MI:0915) by two hybrid (MI:0018)MINT-8046409: NapD (uniprotkb:P0A9I5) and NapA (uniprotkb:P33937) physically interact (MI:0915) by two hybrid (MI:0018)     

NMDA receptors interact with flotillin-1 and -2, lipid raft-associated proteins

N-methyl-d-aspartate receptors (NMDARs) mediate excitatory synaptic transmission in the brain. Here we demonstrate interactions between the NR2A and NR2B subunits of NMDARs with flotillin-1 (flot-1), a lipid raft-associated protein. When mapped, analogous regions in the far distal C-termini of NR2A and NR2B mediate binding to flot-1, and the prohibitin homology domain of flot-1 contains binding sites for NR2A and NR2B. Although NR2B can also directly bind to flot-2 via a separate region of its distal C-terminus, NMDARs were significantly more colocalized with flot-1 than flot-2 in cultured hippocampal neurons. Overall, this study defines a novel interaction between NMDARs and flotillins.

Structured summary

MINT-7013094: NR2A (uniprotkb:Q00959), NR2B (uniprotkb:Q00960) and Flot2 (uniprotkb:Q9Z2S9) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7013147: Flot1 (uniprotkb:Q9Z1E1) physically interacts (MI:0218) with NR2A (uniprotkb:Q00959) by anti bait coimmunoprecipitation (MI:0006)MINT-7013189: Flot1 (uniprotkb:Q9Z1E1) physically interacts (MI:0218) with Flot2 (uniprotkb:Q9Z2S9) by anti bait coimmunoprecipitation (MI:0006)MINT-7013033: NR2A (uniprotkb:Q00959) physically interacts (MI:0218) with Flot1 (uniprotkb:Q9Z1E1) by two hybrid (MI:0018)MINT-7013178: NR1 (uniprotkb:P35439) physically interacts (MI:0218) with Flot2 (uniprotkb:Q9Z2S9) by anti bait coimmunoprecipitation (MI:0006)MINT-7013197, MINT-7013210: NR2B (uniprotkb:Q00960) and NR2A (uniprotkb:Q00959) physically interact (MI:0218) with Flot2 (uniprotkb:Q9Z2S9) by anti bait coimmunoprecipitation (MI:0006)MINT-7013002: NR2B (uniprotkb:Q00960) physically interacts (MI:0218) with Flot1 (uniprotkb:O08917) by two hybrid (MI:0018)MINT-7013117: Flot1 (uniprotkb:Q9Z1E1), NR2B (uniprotkb:Q00960) and NR2A (uniprotkb:Q00959) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7013171: NR1 (uniprotkb:P35439) physically interacts (MI:0218) with Flot1 (uniprotkb:Q9Z1E1) by anti bait coimmunoprecipitation (MI:0006)MINT-7013017: NR2A (uniprotkb:Q00959) physically interacts (MI:0218) with Flot1 (uniprotkb:O08917) by two hybrid (MI:0018)MINT-7013054: NR2B (uniprotkb:Q00960) physically interacts (MI:0218) with Flot1 (uniprotkb:Q9Z1E1) by two hybrid (MI:0018)MINT-7013129: Flot1 (uniprotkb:Q9Z1E1) physically interacts (MI:0218) with NR2B (uniprotkb:Q00960) by anti bait coimmunoprecipitation (MI:0006)MINT-7013155: NR1 (uniprotkb:P35439) physically interacts (MI:0218) with NR2B (uniprotkb:Q00960) by anti bait coimmunoprecipitation (MI:0006)MINT-7013074: NR2B (uniprotkb:Q00960) physically interacts (MI:0218) with Flot2 (uniprotkb:Q9Z2S9) by two hybrid (MI:0018)MINT-7013162: NR1 (uniprotkb:P35439) physically interacts (MI:0218) with NR2A (uniprotkb:Q00959) by anti bait coimmunoprecipitation (MI:0006)     

c-Abl tyrosine kinase interacts with MAVS and regulates innate immune response

The tyrosine kinase, c-Abl, plays important roles in many aspects of cellular function. Previous reports showed that c-Abl is involved in NF-κB signaling. However, the functions of c-Abl in innate immunity are still unknown. Here we demonstrate that the mitochondrial antiviral signaling (MAVS) protein can be physically associated with c-Abl in vivo and in vitro. MAVS interacted with c-Abl through its Card and TM domain. A phosphotyrosine-specific antibody indicated that MAVS was phosphorylated by c-Abl. Functional impairment of c-Abl attenuated MAVS or VSV induced type-I IFN production. Importantly, c-Abl knockdown in MCF7 cells displayed impaired MAVS-mediated NF-κB and IRF3 activation. Taken together, our results suggest that c-Abl modulates innate immune response through MAVS.

Structured summary

MINT-7297498, MINT-7297511, MINT-7297557, MINT-7297574: MAVS (uniprotkb:Q7Z434) physically interacts (MI:0915) with c-Abl (uniprotkb:P00519) by anti tag coimmunoprecipitation (MI:0007)MINT-7297542: c-Abl (uniprotkb:P00519) physically interacts (MI:0915) with MAVS (uniprotkb:Q7Z434) by anti bait coimmunoprecipitation (MI:0006)MINT-7297526: c-Abl (uniprotkb:P00519) physically interacts (MI:0915) with MAVS (uniprotkb:Q7Z434) by far western blotting (MI:0047)     

Interplay between the cpSRP pathway components, the substrate LHCP and the translocase Alb3: An in vivo and in vitro study

The chloroplast signal recognition particle (cpSRP) and its receptor, cpFtsY, posttranslationally target the nuclear-encoded light-harvesting chlorophyll-binding proteins (LHCPs) to the translocase Alb3 in the thylakoid membrane. In this study, we analyzed the interplay between the cpSRP pathway components, the substrate protein LHCP and the translocase Alb3 by using in vivo and in vitro techniques. We propose that cpSRP43 is crucial for the binding of LHCP-loaded cpSRP and cpFtsY to Alb3. In addition, our data suggest that a direct interaction between Alb3 and LHCP contributes to the formation of this complex.

Structured summary

MINT-7992851: Alb3 (uniprotkb:Q8LBP4) physically interacts (MI:0915) with cpSRP43 (uniprotkb:O22265) by two hybrid (MI:0018)MINT-7992897: cpSRP43 (uniprotkb:O22265) and Alb3 (uniprotkb:Q8LBP4) physically interact (MI:0915) by bimolecular fluorescence complementation (MI:0809)MINT-7993251: SRP43 (uniprotkb:O22265) binds (MI:0407) to LHCP (uniprotkb:P27490) by pull down (MI:0096)MINT-7993207: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with ftsY (uniprotkb:O80842), LHCP (uniprotkb:P27490), SRP-54 (uniprotkb:P37106) and Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)MINT-7993272: Alb3 (uniprotkb:Q8LBP4) and LHCB (uniprotkb:P27490) physically interact (MI:0915) by bimolecular fluorescence complementation (MI:0809)MINT-7992960: cpSRP43 (uniprotkb:O22265) binds (MI:0407) to Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)MINT-7993236: Alb3 (uniprotkb:Q8LBP4) binds (MI:0407) to LHCP (uniprotkb:P27490) by pull down (MI:0096)MINT-7993166: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with LHCP (uniprotkb:P27490) and Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)MINT-7993118: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with Alb3 (uniprotkb:Q8LBP4), SRP-54 (uniprotkb:P37106) and LHCP (uniprotkb:P27490) by pull down (MI:0096)MINT-7993046: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with ftsY (uniprotkb:O80842), SRP-54 (uniprotkb:P37106) and Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)MINT-7993004: cpSRP43 (uniprotkb:O22265) physically interacts (MI:0915) with SRP54 (uniprotkb:P37106) and Alb3 (uniprotkb:Q8LBP4) by pull down (MI:0096)     

Deletion of Swm2p selectively impairs trimethylation of snRNAs by trimethylguanosine synthase (Tgs1p)

The 5′ cap trimethylation of small nuclear (snRNAs) and several nucleolar RNAs (snoRNAs) by trimethylguanosine synthase 1 (Tgs1p) is required for efficient pre-mRNA splicing. The previously uncharacterised protein Swm2p interacted with Tgs1p in yeast two-hybrid screens. In the present study we show that Swm2p interacts with the N-terminus of Tgs1p and its deletion impairs pre-mRNA splicing and pre-rRNA processing. The trimethylation of spliceosomal snRNAs and the U3 snoRNA, but not other snoRNAs, was abolished in the absence of Swm2p, indicating that Swm2p is required for a substrate-specific activity of Tgs1p.

Structured summary

MINT-7949608: p53 (uniprotkb:P02340) physically interacts (MI:0915) with large T-antigen (uniprotkb:P03070) by two-hybrid (MI:0018)MINT-7949574: swm2 (uniprotkb:P40342) physically interacts (MI:0915) with swm2 (uniprotkb:P40342) by pull down (MI:0096)MINT-7949556: swm2 (uniprotkb:P40342) physically interacts (MI:0915) with TGS1 (uniprotkb:Q12052) by pull down (MI:0096)MINT-7949587: swm2 (uniprotkb:P40342) physically interacts (MI:0915) with tgs1 (uniprotkb:Q12052) by two-hybrid (MI:0018)MINT-7949641: nop1 (uniprotkb:P15646) colocalizes (MI:0403) with TGS1 (uniprotkb:Q12052) by fluorescence microscopy (MI:0416)MINT-7949627: swm2 (uniprotkb:P40342) and nop1 (uniprotkb:P15646) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7949540: swm2 (uniprotkb:P40342) physically interacts (MI:0915) with TGS1 (uniprotkb:Q12052) by tandem affinity purification (MI:0676)     

Grb14 inhibits FGF receptor signaling through the regulation of PLCγ recruitment and activation

To decipher the mechanism involved in Grb14 binding to the activated fibroblast growth factor receptor (FGFR), we used the bioluminescence resonance energy transfer (BRET) technique and the Xenopus oocyte model. We showed that Grb14 was recruited to FGFR1 into a trimeric complex containing also phospholipase C gamma (PLCγ). The presence of Grb14 altered FGF-induced PLCγ phosphorylation and activation. Grb14-FGFR interaction involved the Grb14-SH2 domain and the FGFR pY766 residue, which is the PLCγ binding site. Our data led to a molecular model whereby Grb14 binding to the phosphorylated FGFR induces a conformational change that unmasks a PLCγ binding motif on Grb14, allowing trapping and inactivation of PLCγ.

Structured summary

MINT-8019680: Grb14 (uniprotkb:O88900) physically interacts (MI:0915) with FGFR1 (uniprotkb:P11362) by anti tag coimmunoprecipitation (MI:0007)MINT-8019693, MINT-8019727: Grb14 (uniprotkb:O88900) physically interacts (MI:0915) with FGFR1 (uniprotkb:P11362) by bioluminescence resonance energy transfer (MI:0012)MINT-8019714, MINT-8019746: PLC gamma1 (uniprotkb:P19174) physically interacts (MI:0915) with FGFR1 (uniprotkb:P11362) by bioluminescence resonance energy transfer (MI:0012)     

Evidence for leptin receptor isoforms heteromerization at the cell surface

Leptin mediates its metabolic effects through several leptin receptor (LEP-R) isoforms. In humans, long (LEPRb) and short (LEPRa,c,d) isoforms are generated by alternative splicing. Most of leptin’s effects are believed to be mediated by the OB-Rb isoform. However, the role of short LEPR isoforms and the possible existence of heteromers between different isoforms are poorly understood. Using BRET1 and optimized co-immunoprecipitation, we observed LEPRa/b and LEPRb/c heteromers located at the plasma membrane and stabilized by leptin. Given the widespread coexpression of LEPRa and LEPRb, our results suggest that LEPRa/b heteromers may represent a major receptor species in most tissues.

Structured summary

MINT-7714817: LEPRb (uniprotkb:P48357-1) physically interacts (MI:0915) with LEPRb (uniprotkb:P48357-1) by anti tag co-immunoprecipitation (MI:0007)MINT-7714785: LEPRc (uniprotkb:P48357-2) physically interacts (MI:0915) with LEPRc (uniprotkb:P48357-2) by bioluminescence resonance energy transfer (MI:0012)MINT-7714951, MINT-7714744: LEPRa (uniprotkb:P48357-3) physically interacts (MI:0915) with LEPRa (uniprotkb:P48357-3) by bioluminescence resonance energy transfer (MI:0012)MINT-7714859: LEPRb (uniprotkb:P48357-1) physically interacts (MI:0915) with LEPRa (uniprotkb:P48357-3) by anti tag co-immunoprecipitation (MI:0007)MINT-7714885, MINT-7714672: LEPRb (uniprotkb:P48357-1) physically interacts (MI:0915) with LEPRb (uniprotkb:P48357-1) by bioluminescence resonance energy transfer (MI:0012)MINT-7714835: LEPRa (uniprotkb:P48357-3) physically interacts (MI:0915) with LEPRa (uniprotkb:P48357-3) by anti tag co-immunoprecipitation (MI:0007)MINT-7714914, MINT-7714723, MINT-7714759: LeprB (uniprotkb:P48357-1) physically interacts (MI:0915) with LEPRa (uniprotkb:P48357-3) by bioluminescence resonance energy transfer (MI:0012)MINT-7714703, MINT-7714936, MINT-7714772: LEPRb (uniprotkb:P48357-1) physically interacts (MI:0915) with LEPRc (uniprotkb:P48357-2) by bioluminescence resonance energy transfer (MI:0012)MINT-7714872: LEPRb (uniprotkb:P48357-1) physically interacts (MI:0915) with LEPRc (uniprotkb:P48357-2) by anti tag co-immunoprecipitation (MI:0007)     

The β1 subunit of Na/K-ATPase interacts with BKCa channels and affects their steady-state expression on the cell surface

Large conductance Ca²⁺-activated K⁺ channels (BK_Ca) encoded by the Slo1 gene play a role in the physiological regulation of many cell types. Here, we show that the β1 subunit of Na⁺/K⁺-ATPase (NKβ1) interacts with the cytoplasmic COOH-terminal region of Slo1 proteins. Reduced expression of endogenous NKβ1 markedly inhibits evoked BK_Ca currents with no apparent effect on their gating. In addition, NKβ1 down-regulated cells show decreased density of Slo1 subunits on the cell surface.

Structured summary

MINT-7260438, MINT-7260555: Slo1 (uniprotkb:Q8AYS8) physically interacts (MI:0915) with NKbeta1 (uniprotkb:P08251) by anti bait coimmunoprecipitation (MI:0006)MINT-7260587, MINT-7260606, MINT-7260619, MINT-7260632: Slo1 (uniprotkb:Q08460) physically interacts (MI:0915) with NKbeta 1 (uniprotkb:P08251) by pull down (MI:0416)MINT-7260570: NKbeta1 (uniprotkb:P08251) and Slo1 (uniprotkb:Q8AYS8) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7260414: Slo1 (uniprotkb:Q08460) physically interacts (MI:0915) with NKbeta1 (uniprotkb:P08251) by two hybrid (MI:0018)     

The scaffold protein JIP3 functions as a downstream effector of the small GTPase ARF6 to regulate neurite morphogenesis of cortical neurons

The small GTPase ADP-ribosylation factor 6 (ARF6) plays crucial roles in a wide variety of cell functions. To better understand the molecular mechanisms of ARF6-mediated signaling and cellular functions, we sought new ARF6-binding proteins in the mouse brain. We identified the signaling scaffold protein JNK-interacting protein 3 (JIP3), which is exclusively expressed in neurons, as a downstream effector of ARF6. Overexpression of a unique dominant negative mutant of ARF6, which was unable to interact with JIP3, and knockdown of JIP3 in mouse cortical neurons stimulated the elongation and branching of neurites. These results provide evidence that ARF6/JIP3 signaling regulates neurite morphogenesis.

Structured summary

MINT-7892698: PIP5K gamma 661 (uniprotkb:O70161) physically interacts (MI:0915) with Arf6 (uniprotkb:P62331) by anti tag coimmunoprecipitation (MI:0007)MINT-7892333, MINT-7892573, MINT-7892594, MINT-7892629, MINT-7892644, MINT-7892522, MINT-7892716: Arf6 (uniprotkb:P62331) physically interacts (MI:0915) with JLP (uniprotkb:Q58A65) by anti tag coimmunoprecipitation (MI:0007)MINT-7892509: Arf6 (uniprotkb:P62331) physically interacts (MI:0915) with JIP3 (uniprotkb:Q9ESN9) by pull down (MI:0096)MINT-7892770: Arf6 (uniprotkb:P62331) binds (MI:0407) to JIP3 (uniprotkb:Q9ESN9) by pull down (MI:0096)MINT-7892755: Arf6 (uniprotkb:P62331) binds (MI:0407) to JLP (uniprotkb:Q58A65) by pull down (MI:0096)MINT-7892289, MINT-7892314: Arf6 (uniprotkb:P62331) physically interacts (MI:0915) with JLP (uniprotkb:Q58A65) by pull down (MI:0096)MINT-7892353, MINT-7892615, MINT-7892657, MINT-7892672, MINT-7892549, MINT-7892738: Arf6 (uniprotkb:P62331) physically interacts (MI:0915) with JIP3 (uniprotkb:Q9ESN9) by anti tag coimmunoprecipitation (MI:0007)     

Cereblon is expressed in the retina and binds to voltage-gated chloride channels

The function of the central nervous system depends on the correct regulation of ion channels by interacting proteins. Here, we identified cereblon as a new interactor of the voltage-gated chloride channel ClC-2. A distal region of the ClC-2 C-terminus interacts with the Lon domain of cereblon. Cereblon is expressed in several brain regions including the retina. There, we detected cereblon in nuclear and synaptic layers and localized the protein in the same subcellular region of bipolar cell bodies previously reported to express ClC-2. Our data suggest that cereblon might be associated with voltage-gated chloride channels in the central nervous system.

Structured summary

MINT-6823070: CIC-2 (uniprotkb:O54822) physically interacts (MI:0218) with CRBN (uniprotkb:Q0P564) by two hybrid (MI:0018) MINT-6823160, MINT-6823197: CIC-2 (uniprotkb:O54822) physically interacts (MI:0218) with CRBN (uniprotkb:Q56AP7) by pull down (MI:0096) MINT-6823105: CIC-2 (uniprotkb:O54822) physically interacts (MI:0218) with IK (uniprotkb:A4FUY8) by two hybrid (MI:0018)     

The interaction between EAP30 and ELL is modulated by MCM2

ELL-associated protein 30 (EAP30) was initially characterized as a component of the Holo-ELL complex, which contains the elongation factor ELL. Both ELL and Holo-ELL stimulate RNA pol II elongation in vitro. However, ELL and not Holo-ELL inhibits RNA pol II initiation. It is not clear how these two discrete functions of ELL are regulated. Here we report that mini-chromosome maintenance 2 (MCM2) binds to EAP30 and show that MCM2 competes with ELL for binding to EAP30 thus potentially modulating the stability of Holo-ELL.

Structured summary

MINT-7277033: EAP30 (uniprotkb:Q96H20) physically interacts (MI:0915) with RPB1 (uniprotkb:P24928) by anti tag coimmunoprecipitation (MI:0007)MINT-7277085: EAP30 (uniprotkb:Q96H20) binds (MI:0407) to ELL (uniprotkb:P55199) by pull down (MI:0096)MINT-7277072: EAP30 (uniprotkb:Q96H20) physically interacts (MI:0915) with ELL (uniprotkb:P55199) by anti tag coimmunoprecipitation (MI:0007)MINT-7277100: EAP30 (uniprotkb:Q96H20) physically interacts (MI:0915) with ELL (uniprotkb:P55199) by competition binding (MI:0405)MINT-7277153: MCM2 (uniprotkb:P49736) binds (MI:0407) to ELL (uniprotkb:P55199) by pull down (MI:0096)MINT-7276989: EAP30 (uniprotkb:Q96H20) physically interacts (MI:0915) with MCM2 (uniprotkb:P49736) by pull down (MI:0096)MINT-7277005: EAP30 (uniprotkb:Q96H20) physically interacts (MI:0915) with RPB1 (uniprotkb:P24928) by pull down (MI:0096)MINT-7276960, MINT-7277168: MCM2 (uniprotkb:P49736) physically interacts (MI:0915) with EAP30 (uniprotkb:Q96H20) by two hybrid (MI:0018)MINT-7276971, MINT-7277121, MINT-7277137: MCM2 (uniprotkb:P49736) binds (MI:0407) to EAP30 (uniprotkb:Q96H20) by pull down (MI:0096)MINT-7277018, MINT-7277061: EAP30 (uniprotkb:Q96H20) physically interacts (MI:0915) with MCM2 (uniprotkb:P49736) by anti tag coimmunoprecipitation (MI:0007)     

Proliferating cell nuclear antigen in the cytoplasm interacts with components of glycolysis and cancer

Proliferating cell nuclear antigen (PCNA) is involved in a wide range of functions in the nucleus. However, a substantial amount of PCNA is also present in the cytoplasm, although their function is unknown. Here we show, through Far-Western blotting and mass spectrometry, that PCNA is associated with several cytoplasmic oncoproteins, including elongation factor, malate dehydrogenase, and peptidyl-prolyl isomerase. Surprisingly, PCNA is also associated with six glycolytic enzymes that are involved in the regulation of steps 4-9 in the glycolysis pathway.

Structured summary

MINT-7995351: G3P (uniprotkb:P04406) and PCNA (uniprotkb:P12004) colocalize (MI:0403) by fluorescencemicroscopy (MI:0416)MINT-7995334: ENOA (uniprotkb:P06733) and PCNA (uniprotkb:P12004) colocalize (MI:0403) by fluorescencemicroscopy (MI:0416)MINT-7995368: ALDOA (uniprotkb:P04075) and PCNA (uniprotkb:P12004) colocalize (MI:0403) by fluorescencemicroscopy (MI:0416)MINT-7995141: G3P (uniprotkb:P04406) binds (MI:0407) to PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995182: ENOA (uniprotkb:P06733) binds (MI:0407) to PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995132: G3P (uniprotkb:P04406) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995228: PRDX6 (uniprotkb:P30041) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995220: CAH2 (uniprotkb:P00918) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995114: Triosephosphateisomerase (uniprotkb:P60174) binds (MI:0407) to PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995244: K2C7 (uniprotkb:P08729) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995252: ANXA2 (uniprotkb:P07355) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995122: Triosephosphateisomerase (uniprotkb:P60174) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995093: ALDOA (uniprotkb:P04075) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995148: PGK1 (uniprotkb:P00558) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995158: PGAM1 (uniprotkb:P18669) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995166: PGAM1 (uniprotkb:P18669) binds (MI:0407) to PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995105: ALDOA (uniprotkb:P04075) binds (MI:0407) to PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995260: PPIA (uniprotkb:P62937) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995173: ENOA (uniprotkb:P06733) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995268: EF1A (uniprotkb:P68104) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995236: MDHM (uniprotkb:P40926) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995189: RSSA (uniprotkb:P08865) physicallyinteracts (MI:0915) with PCNA (uniprotkb:P12004) by farwesternblotting (MI:0047)MINT-7995282: PCNA (uniprotkb:P12004) physicallyinteracts (MI:0915) with ALDOA (uniprotkb:P00883) and G3P (uniprotkb:P46406) by antibaitcoimmunoprecipitation (MI:0006).