ARF-dependent regulation of ATM and p53 associated KZNF (Apak) protein activity in response to oncogenic stress

The KRAB-type zinc-finger protein Apak (ATM and p53 associated KZNF protein) specifically suppresses p53-mediated apoptosis. Upon DNA damage, Apak is phosphorylated and inhibited by ATM kinase, resulting in p53 activation. However, how Apak is regulated in response to oncogenic stress remains unknown. Here we show that upon oncogene activation, Apak is inhibited in the tumor suppressor ARF-dependent but ATM-independent manner. Oncogene-induced ARF protein directly interacts with Apak and competes with p53 to bind to Apak, resulting in Apak dissociation from p53. Thus, Apak is differentially regulated in the ARF and ATM-dependent manner in response to oncogenic stress and DNA damage, respectively.

Structured summary

MINT-7989670: p53 (uniprotkb:P04637) binds (MI:0407) to APAK (uniprotkb:Q8TAQ5) by pull down (MI:0096)MINT-7989812: HDM2 (uniprotkb:Q00987) physically interacts (MI:0915) with ARF (uniprotkb:Q8N726-1) by anti bait coimmunoprecipitation (MI:0006)MINT-7989603, MINT-7989626: APAK (uniprotkb:Q8TAQ5) physically interacts (MI:0915) with ARF (uniprotkb:Q8N726-1) by anti bait coimmunoprecipitation (MI:0006)MINT-7989653: ARF (uniprotkb:Q8N726-1) binds (MI:0407) to APAK (uniprotkb:Q8TAQ5) by pull down (MI:0096)MINT-7989686, MINT-7989705, MINT-7989747:APAK (uniprotkb:Q8TAQ5) physically interacts (MI:0915) with ARF (uniprotkb:Q8N726-1) by anti tag coimmunoprecipitation (MI:0007)MINT-7989724: APAK (uniprotkb:Q8TAQ5) physically interacts (MI:0914) with ARF (uniprotkb:Q8N726-1) and p53 (uniprotkb:P04637) by anti tag coimmunoprecipitation (MI:0007)MINT-7989635: ARF (uniprotkb:Q8N726-1) and APAK (uniprotkb:Q8TAQ5) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7989584, MINT-7989773: APAK (uniprotkb:Q8TAQ5) physically interacts (MI:0915) with p53 (uniprotkb:P04637) by anti tag coimmunoprecipitation (MI:0007)     

Mdmx enhances p53 ubiquitination by altering the substrate preference of the Mdm2 ubiquitin ligase

mdm2 and mdmx oncogenes play essential yet non-redundant roles in synergistic inactivation of the tumor suppressor, p53. While Mdm2 inhibits p53 activity mainly by augmenting its ubiquitination, the functional role of Mdmx on p53 ubiquitination remains obscure. In transfected H1299 cells, Mdmx augmented Mdm2-mediated ubiquitination of p53. In in vitro ubiquitination assays, the Mdmx/Mdm2 heteromeric complex, in comparison to the Mdm2 homomer, showed enhanced ubiquitinase activity toward p53 and the reduced auto-ubiquitination of Mdm2. Alteration of the substrate specificity via binding to Mdmx may contribute to efficient ubiquitination and inactivation of p53 by Mdm2.

Structured summary

MINT-7219995: P53 (uniprotkb:P04637) physically interacts (MI:0914) with Ubiquitin (uniprotkb:P62988) by anti bait coimmunoprecipitation (MI:0006)MINT-7220023: Ubiquitin (uniprotkb:P62988) physically interacts (MI:0914) with P53 (uniprotkb:P04637) by pull down (MI:0096)     

NLS-mediated NPC functions of the nucleoporin Pom121

RanGTP mediates nuclear import and mitotic spindle assembly by dissociating import receptors from nuclear localization signal (NLS) bearing proteins. We investigated the interplay between import receptors and the transmembrane nucleoporin Pom121. We found that Pom121 interacts with importin α/β and a group of nucleoporins in an NLS-dependent manner. In vivo, replacement of Pom121 with an NLS mutant version resulted in defective nuclear transport, induction of aberrant cytoplasmic membrane stacks and decreased cell viability. We propose that the NLS sites of Pom121 affect its function in NPC assembly both by influencing nucleoporin interactions and pore membrane structure.

Structured summary

MINT-7951230: pom121 (uniprotkb:Q5EWX9) physically interacts (MI:0914) with nup155 (uniprotkb:O75694), Nup133 (uniprotkb:Q8WUM0) and Importin beta (uniprotkb:Q14974) by pull down (MI:0096)MINT-7951210: pom121 (uniprotkb:Q5EWX9) physically interacts (MI:0915) with Importin alpha (uniprotkb:P52170) and Importin beta (uniprotkb:P52297) by pull down (MI:0096)MINT-7951183: pom121 (uniprotkb:Q5EWX9) physically interacts (MI:0914) with nup155 (uniprotkb:Q7ZWL0), nup160 (uniprotkb:P83722), nup205 (uniprotkb:Q642R6), nup93 (uniprotkb:Q7ZX96), Importin beta (uniprotkb:P52297) and nup62 (uniprotkb:Q91349) by pull down (MI:0096)MINT-7951416: pom121 (uniprotkb:Q5EWX9) physically interacts (MI:0914) with nup155 (uniprotkb:Q7ZWL0), nup93 (uniprotkb:Q7ZX96) and Importin beta (uniprotkb:P52297) by pull down (MI:0096)MINT-7951276: pom121 (uniprotkb:Q5EWX9) physically interacts (MI:0914) with nup155 (uniprotkb:Q7ZWL0), nup205 (uniprotkb:Q642R6), nup93 (uniprotkb:Q7ZX96), Importin beta (uniprotkb:P52297) and nup62 (uniprotkb:Q91349) by pull down (MI:0096)MINT-7951306, MINT-7951362: pom121 (uniprotkb:Q5EWX9) physically interacts (MI:0914) with nup155 (uniprotkb:Q7ZWL0), nup160 (uniprotkb:P83722), nup93 (uniprotkb:Q7ZX96), Importin beta (uniprotkb:P52297) and nup62 (uniprotkb:Q91349) by pull down (MI:0096)     

FKBP25, a novel regulator of the p53 pathway, induces the degradation of MDM2 and activation of p53

The p53 tumour suppressor protein is tightly controlled by the E3 ubiquitin ligase, mouse double minute 2 (MDM2), but maintains MDM2 expression as part of a negative feedback loop. We have identified the immunophilin, 25 kDa FK506-binding protein (FKBP25), previously shown to be regulated by p53-mediated repression, as an MDM2-interacting partner. We show that FKBP25 stimulates auto-ubiquitylation and proteasomal degradation of MDM2, leading to the induction of p53. Depletion of FKBP25 by siRNA leads to increased levels of MDM2 and a corresponding reduction in p53 and p21 levels. These data are consistent with the idea that FKBP25 contributes to regulation of the p53-MDM2 negative feedback loop.

Structured summary

MINT-6823686:MDM2 (uniprotkb:Q00987) physically interacts (MI:0218) with FKBP25 (uniprotkb:Q00688) by anti bait coimmunoprecipitation (MI:0006)MINT-6823707, MINT-6823722:MDM2 (uniprotkb:Q00987) physically interacts (MI:0218) with FKBP25 (uniprotkb:Q62446) by pull down (MI:0096)MINT-6823775:P53 (uniprotkb:Q04637) physically interacts (MI:0218) with MDM2 (uniprotkb:Q00987) by anti bait coimmunoprecipitation (MI:0006)MINT-6823735, MINT-6823749:FKBP25 (uniprotkb:Q62446) binds (MI:0407) to MDM2 (uniprotkb:Q00987) by pull down (MI:0096)MINT-6823761:Ubiquitin (UNIPROTKB:62988)P physically interacts (MI:0218) with MDM2 (uniprotkb:Q00987) by pull down (MI:0096)MINT-6823669:MDM2 (uniprotkb:Q00987) physically interacts (MI:0218) with FKBP25 (uniprotkb:Q00688) by two hybrid (MI:0018)     

p53 inhibits tumor cell invasion via the degradation of snail protein in hepatocellular carcinoma

The tumor suppressor protein p53 is a key regulator of cell cycle arrest and apoptosis. Snail protein regulates cancer-associated malignancies. However, the relationship between p53 and Snail proteins in hepatocellular carcinoma (HCC) has not been completely understood. To determine whether Snail and p53 contribute to hepatocarcinogenesis, we analyzed the expression of Snail proteins in p53-overexpressing HCC cells. We found that p53 wild-type (WT) induced the degradation of Snail protein via murine double minute 2-mediated ubiquitination, whereas p53 mutant did not induce Snail degradation. As we expected, only p53WT induced endogenous Snail protein degradation and inhibited tumor cell invasion. These findings contribute to a better understanding of the role of p53 mutation and Snail overexpression as a late event in hepatocarcinogenesis.

Structured summary

MINT-7718917: p53 (uniprotkb:P04637) physically interacts (MI:0915) with Snai1 (uniprotkb:O95863) by anti bait coimmunoprecipitation (MI:0006)MINT-7719877: Snai1 (uniprotkb:O95863) physically interacts (MI:0915) with ubiquitin (uniprotkb:P62988) by anti tag coimmunoprecipitation (MI:0007)MINT-7718928: Snai1 (uniprotkb:O95863) physically interacts (MI:0915) with p53 (uniprotkb:P04637) by anti tag coimmunoprecipitation (MI:0007)MINT-7718939: Snai1 (uniprotkb:O95863) physically interacts (MI:0915) with MDM2 (uniprotkb:Q00987) by anti tag coimmunoprecipitation (MI:0007)     

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)     

Interaction specificity of Arabidopsis 14-3-3 proteins with phototropin receptor kinases

Phototropin receptor kinases play an important role in optimising plant growth in response to blue light. Much is known regarding their photochemical reactivity, yet little progress has been made to identify downstream signalling components. Here, we isolated several interacting proteins for Arabidopsis phototropin 1 (phot1) by yeast two-hybrid screening. These include members of the NPH3/RPT2 (NRL) protein family, proteins associated with vesicle trafficking, and the 14-3-3 lambda (λ) isoform from Arabidopsis. 14-3-3λ and phot1 were found to colocalise and interact in vivo. Moreover, 14-3-3 binding to phot1 was limited to non-epsilon 14-3-3 isoforms and was dependent on key sites of receptor autophosphorylation. No 14-3-3 binding was detected for Arabidopsis phot2, suggesting that 14-3-3 proteins are specific to phot1 signalling.

Structured summary

MINT-7146953: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with ARF7 (uniprotkb:Q9LFJ7) by two hybrid (MI:0018)MINT-7147335: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 phi (uniprotkb:P46077) by far Western blotting (MI:0047)MINT-7146854: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with RPT2 (uniprotkb:Q682S0) by two hybrid (MI:0018)MINT-7147215: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 lambda (uniprotkb:P48349) by anti tag coimmunoprecipitation (MI:0007)MINT-7147044, MINT-7147185, MINT-7147200, MINT-7147413: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 lambda (uniprotkb:P48349) by far Western blotting (MI:0047)MINT-7146983: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with 14-3-3 lambda (uniprotkb:P48349) by two hybrid (MI:0018)MINT-7146871: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with NPH3-like (uniprotkb:Q9S9Q9) by two hybrid (MI:0018)MINT-7146905: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with ARF2 (uniprotkb:Q9M1P5) by two hybrid (MI:0018)MINT-7147364: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 upsilon (uniprotkb:P42645) by far Western blotting (MI:0047)MINT-7147234: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 kappa (uniprotkb:P48348) by far Western blotting (MI:0047)     

Anti-apoptotic protein TCTP controls the stability of the tumor suppressor p53

In this study, we identified p53 as a novel TCTP-interacting protein using TCTP as bait. Also, we determined the critical binding sites between TCTP and p53. To elucidate the functional consequence of the interaction, we developed the overexpression and inhibition system of TCTP and p53 expression. Overexpression of TCTP in lung carcinoma cells reversed p53 mediated apoptosis and inhibition of TCTP expression by small interfering RNA increased apoptosis of lung carcinoma cells. Moreover, it was observed that TCTP overexpression promotes degradation of p53. These results clearly indicate that the interaction between TCTP and p53 prevents apoptosis by destabilizing p53. Thus, TCTP acts as a negative regulator of apoptosis in lung cancer.

Structured summary

MINT-8057107, MINT-8057116: p53 (uniprotkb:P04637) physically interacts (MI:0915) with TCTP (uniprotkb:P13693) by anti bait coimmunoprecipitation (MI:0006)MINT-8057141: TCTP (uniprotkb:P13693) physically interacts (MI:0915) with p53 (uniprotkb:P04637) by two hybrid pooling approach (MI:0398)MINT-8057126: p53 (uniprotkb:P04637) physically interacts (MI:0915) with TCTP (uniprotkb:P13693) by anti tag coimmunoprecipitation (MI:0007) MINT-8057160: TCTP (uniprotkb:P13693) physically interacts (MI:0915) with p53 (uniprotkb:P04637) by two hybrid (MI:0018)     

MCL-1ES, a novel variant of MCL-1, associates with MCL-1L and induces mitochondrial cell death

Myeloid cell leukemia-1 (MCL-1L) is a pro-survival member of the BCL-2 family that promotes cell survival. In this study, we identify a new splicing variant of human MCL-1 that encodes MCL-1ES (extra short). Sequence analysis indicates that this variant results from splicing within the first coding exon of MCL-1 at a non-canonical GC-AG donor-acceptor pair. The deduced sequence of MCL-1ES encodes a protein of 197 amino acids, and the PEST (proline, glutamic acid, serine, and threonine) motifs present in MCL-1L are absent. MCL-1ES interacts with MCL-1L and induces mitochondrial cell death, suggesting that alternative splicing of MCL-1 may control the fate of cells.

Structured summary

MINT-7255705, MINT-7255718, MINT-7255731, MINT-7255743:MCL1-ES (uniprotkb:Q07820-2) physically interacts (MI:0914) with MCL1-1L (uniprotkb:Q07820-1) by anti tag coimmunoprecipitation (MI:0007)MINT-7255771:MCL1-ES (uniprotkb:Q07820-2) physically interacts (MI:0914) with Beta actin (uniprotkb:P60709) by anti tag coimmunoprecipitation (MI:0007)MINT-7255781:MCL1-ES (uniprotkb:Q07820-2) physically interacts (MI:0914) with GAPDH (uniprotkb:P04406) by anti tag coimmunoprecipitation (MI:0007)MINT-7255756:MCL1-ES (uniprotkb:Q07820-2) physically interacts (MI:0914) with COX IV (uniprotkb:P13073) by anti tag coimmunoprecipitation (MI:0007)     

S100 proteins regulate the interaction of Hsp90 with Cyclophilin 40 and FKBP52 through their tetratricopeptide repeats

S100 proteins are a subfamily of the EF-hand type calcium sensing proteins, the exact biological functions of which have not been clarified yet. In this work, we have identified Cyclophilin 40 (CyP40) and FKBP52 (called immunophilins) as novel targets of S100 proteins. These immunophilins contain a tetratricopeptide repeat (TPR) domain for Hsp90 binding. Using glutathione-S transferase pull-down assays and immunoprecipitation, we have demonstrated that S100A1 and S100A2 specifically interact with the TPR domains of FKBP52 and CyP40 in a Ca²⁺-dependent manner, and lead to inhibition of the CyP40-Hsp90 and FKBP52-Hsp90 interactions. These findings have suggested that the Ca²⁺/S100 proteins are TPR-targeting regulators of the immunophilins-Hsp90 complex formations.

Structured summary

MINT-7710442: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0915) with S100A6 (uniprotkb:P06703) by competition binding (MI:0405)MINT-7710192: Cyp40 (uniprotkb:P26882) binds (MI:0407) to S100A1 (uniprotkb:P35467) by pull down (MI:0096)MINT-7710412: Cyp40 (uniprotkb:P26882) physically interacts (MI:0915) with S100A2 (uniprotkb:P29034) by competition binding (MI:0405)MINT-7710374: FKBP52 (uniprotkb:Q02790) binds (MI:0407) to S100A2 (uniprotkb:P29034) by pull down (MI:0096)MINT-7710452: Cyp40 (uniprotkb:P26882) physically interacts (MI:0914) with S100A2 (uniprotkb:P29034) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710387: FKBP52 (uniprotkb:Q02790) binds (MI:0407) to S100A6 (uniprotkb:P06703) by pull down (MI:0096)MINT-7710279: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0915) with S100A1 (uniprotkb:P35467) by competition binding (MI:0405)MINT-7710224: FKBP52 (uniprotkb:Q02790) binds (MI:0407) to Hsp90 (uniprotkb:P07900) by pull down (MI:0096)MINT-7710464: Cyp40 (uniprotkb:P26882) physically interacts (MI:0914) with S100A6 (uniprotkb:P06703) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710249: Cyp40 (uniprotkb:P26882) binds (MI:0407) to Hsp90 (uniprotkb:P07900) by pull down (MI:0096)MINT-7710422: Cyp40 (uniprotkb:P26882) physically interacts (MI:0915) with S100A6 (uniprotkb:P06703) by competition binding (MI:0405)MINT-7710348: Cyp40 (uniprotkb:P26882) binds (MI:0407) to S100A2 (uniprotkb:P29034) by pull down (MI:0096)MINT-7710208: FKBP52 (uniprotkb:Q02790) binds (MI:0407) to S100A1 (uniprotkb:P35467) by pull down (MI:0096)MINT-7710265: Cyp40 (uniprotkb:P26882) physically interacts (MI:0915) with S100A1 (uniprotkb:P35467) by competition binding (MI:0405)MINT-7710361: Cyp40 (uniprotkb:P26882) binds (MI:0407) to S100A6 (uniprotkb:P06703) by pull down (MI:0096)MINT-7710476: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0914) with S100A2 (uniprotkb:P29034) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710316: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0914) with S100A1 (uniprotkb:P35467) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710432: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0915) with S100A2 (uniprotkb:P29034) by competition binding (MI:0405)MINT-7710488: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0914) with S100A6 (uniprotkb:P06703) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710329: S100A6 (uniprotkb:P14069) physically interacts (MI:0914) with FKBP52 (uniprotkb:P30416) and Cyp40 (uniprotkb:Q08752) by anti bait coimmunoprecipitation (MI:0006)MINT-7710295: Cyp40 (uniprotkb:P26882) physically interacts (MI:0914) with Hsp90 (uniprotkb:P07900) and S100A1 (uniprotkb:P35467) by anti tag coimmunoprecipitation (MI:0007)     

Polo-like kinase-1 phosphorylates MDM2 at Ser260 and stimulates MDM2-mediated p53 turnover

The E3 ubiqutin ligase, murne double-minute clone 2 (MDM2), promotes the degradation of p53 under normal homeostatic conditions. Several serine residues within the acidic domain of MDM2 are phosphorylated to maintain its activity but become hypo-phosphorylated following DNA damage, leading to inactivation of MDM2 and induction of p53. However, the signalling pathways that mediate these phosphorylation events are not fully understood. Here we show that the oncogenic and cell cycle-regulatory protein kinase, polo-like kinase-1 (PLK1), phosphorylates MDM2 at one of these residues, Ser260, and stimulates MDM2-mediated turnover of p53. These data are consistent with the idea that deregulation of PLK1 during tumourigenesis may help suppress p53 function.

Structured summary

MINT-7266353: MDM2 (uniprotkb:Q00987) physically interacts (MI:0915) with PLK1 (uniprotkb:P53350) by pull down (MI:0096)MINT-7266344, MINT-7266329: MDM2 (uniprotkb:Q00987) physically interacts (MI:0915) with PLK1 (uniprotkb:P53350) by anti bait coimmunoprecipitation (MI:0006)MINT-7266250: PLK1 (uniprotkb:P53350) phosphorylates (MI:0217) p53 (uniprotkb:P04637) by protein kinase assay (MI:0424)MINT-7266241, MINT-7266318: PLK1 (uniprotkb:P53350) phosphorylates (MI:0217) MDM2 (uniprotkb:P23804) by protein kinase assay (MI:0424)MINT-7266231, MINT-7266805, MINT-7266264, MINT-7266299: PLK1 (uniprotkb:P53350) phosphorylates (MI:0217) MDM2 (uniprotkb:Q00987) by protein kinase assay (MI:0424)     

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)     

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)     

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)     

Interactions between membrane-bound cellulose synthases involved in the synthesis of the secondary cell wall

It has not yet been reported how the secondary CESA (cellulose synthase) proteins are organized in the rosette structure. A membrane-based yeast two-hybrid (MbYTH) approach was used to analyze the interactions between the CESA proteins involved in secondary cell wall synthesis of Arabidopsis and the findings were confirmed in planta by bimolecular fluorescence complementation (BiFC) assay. Results indicated that although all CESA proteins can interact with each other, only CESA4 is able to form homodimers. A model is proposed for the secondary rosette structure. The RING-motif proved not to be essential for the interaction between the CESA proteins.

Structured summary

MINT-6951243: PIP2-1 (uniprotkb:P43286) physically interacts (MI:0218) with PIP2-1 (uniprotkb:P43286) by bimolecular fluorescence complementation (MI:0809)MINT-6950816: CESA4 (uniprotkb:Q84JA6) physically interacts (MI:0218) withCESA4 (uniprotkb:Q84JA6) by membrane bound complementation assay (MI:0230)MINT-6951056, MINT-6951071, MINT-6951088, MINT-6951103: CESA7 (uniprotkb:Q9SWW6) physically interacts (MI:0218) with CESA4 (uniprotkb:Q84JA6) by bimolecular fluorescence complementation (MI:0809)MINT-6950949, MINT-6950990: CESA4 (uniprotkb:Q84JA6) physically interacts (MI:0218) with CESA8 (uniprotkb:Q8LPK5) by membrane bound complementation assay (MI:0230)MINT-6950909, MINT-6951030: CESA4 (uniprotkb:Q8LPK5) physically interacts (MI:0218) with CESA7 (uniprotkb:Q9SWW6) by membrane bound complementation assay (MI:0230)MINT-6951042: CESA4 (uniprotkb:Q84JA6) physically interacts (MI:0218) with CESA4 (uniprotkb:Q84JA6) by bimolecular fluorescence complementation (MI:0809)MINT-6951004, MINT-6951016: CESA8 (uniprotkb:Q8LPK5) physically interacts (MI:0218) with CESA7 (uniprotkb:Q9SWW6) by membrane bound complementation assay (MI:0230)MINT-6951217, MINT-6951230: CESA4 (uniprotkb:Q84JA6) physically interacts (MI:0218) with CESA8 (uniprotkb:Q8LPK5) by bimolecular fluorescence complementation (MI:0809)MINT-6951120, MINT-6951140, MINT-6951156, MINT-6951170, MINT-6951185: CESA8 (uniprotkb:Q8LPK5) physically interacts (MI:0218) withCESA7 (uniprotkb:Q9SWW6) by bimolecular fluorescence complementation (MI:0809)MINT-6951199: CESA8 (uniprotkb:Q8LPK5) physically interacts (MI:0218) withCESA8 (uniprotkb:Q8LPK5) by bimolecular fluorescence complementation (MI:0809)