Correction to: Genetic Analysis of Migration Pattern of Female Bonobos (Pan paniscus) Among Three Neighboring Groups

International Journal of Primatology - The original version of this article unfortunately contained mistakes. The changes are shown below:     

N-Terminal α7 Deletion of the Proteasome 20S Core Particle Substitutes for Yeast PI31 Function

The proteasome core particle (CP) is a conserved protease complex that is formed by the stacking of two outer α-rings and two inner β-rings. The α-ring is a heteroheptameric ring of subunits α1 to α7 and acts as a gate that restricts entry of substrate proteins into the catalytic cavity formed by the two abutting β-rings. The 31-kDa proteasome inhibitor (PI31) was originally identified as a protein that binds to the CP and inhibits CP activity in vitro, but accumulating evidence indicates that PI31 is required for physiological proteasome activity. To clarify the in vivo role of PI31, we examined the Saccharomyces cerevisiae PI31 ortholog Fub1. Fub1 was essential in a situation where the CP assembly chaperone Pba4 was deleted. The lethality of Δfub1 Δpba4 was suppressed by deletion of the N terminus of α7 (α7ΔN), which led to the partial activation of the CP. However, deletion of the N terminus of α3, which activates the CP more efficiently than α7ΔN by gate opening, did not suppress Δfub1 Δpba4 lethality. These results suggest that the α7 N terminus has a role in CP activation different from that of the α3 N terminus and that the role of Fub1 antagonizes a specific function of the α7 N terminus.     

Casein Kinase 1γ Ensures Monopolar Growth Polarity under Incomplete DNA Replication Downstream of Cds1 and Calcineurin in Fission Yeast

Cell polarity is essential for various cellular functions during both proliferative and developmental stages, and it displays dynamic alterations in response to intracellular and extracellular cues. However, the molecular mechanisms underlying spatiotemporal control of polarity transition are poorly understood. Here, we show that fission yeast Cki3 (a casein kinase 1γ homolog) is a critical regulator to ensure persistent monopolar growth during S phase. Unlike the wild type, cki3 mutant cells undergo bipolar growth when S phase is blocked, a condition known to delay transition from monopolar to bipolar growth (termed NETO [new end takeoff]). Consistent with this role, Cki3 kinase activity is substantially increased, and cells lose their viability in the absence of Cki3 upon an S-phase block. Cki3 acts downstream of the checkpoint kinase Cds1/Chk2 and calcineurin, and the latter physically interacts with Cki3. Autophosphorylation in the C terminus is inhibitory toward Cki3 kinase activity, and calcineurin is responsible for its dephosphorylation. Cki3 localizes to the plasma membrane, and this localization requires the palmitoyltransferase complex Erf2-Erf4. Membrane localization is needed not only for proper NETO timing but also for Cki3 kinase activity. We propose that Cki3 acts as a critical inhibitor of cell polarity transition under S-phase arrest.     

Microbial Production of Aliphatic (S)-Epoxyalkanes by Using Rhodococcus sp. Strain ST-10 Styrene Monooxygenase Expressed in Organic-Solvent-Tolerant Kocuria rhizophila DC2201

We describe the development of biocatalysis for producing optically pure straight-chain (S)-epoxyalkanes using styrene monooxygenase of Rhodococcus sp. strain ST-10 (RhSMO). RhSMO was expressed in the organic solvent-tolerant microorganism Kocuria rhizophila DC2201, and the bioconversion reaction was performed in an organic solvent-water biphasic reaction system. The biocatalytic process enantioselectively converted linear terminal alkenes to their corresponding (S)-epoxyalkanes using glucose and molecular oxygen. When 1-heptene and 6-chloro-1-hexene were used as substrates (400 mM) under optimized conditions, 88.3 mM (S)-1,2-epoxyheptane and 246.5 mM (S)-1,2-epoxy-6-chlorohexane, respectively, accumulated in the organic phase with good enantiomeric excess (ee; 84.2 and 95.5%). The biocatalysis showed broad substrate specificity toward various aliphatic alkenes, including functionalized and unfunctionalized alkenes, with good to excellent ee. Here, we demonstrate that this biocatalytic system is environmentally friendly and useful for producing various enantiopure (S)-epoxyalkanes.     

Calcineurin ensures a link between the DNA replication checkpoint and microtubule-dependent polarized growth

Microtubules are central to eukaryotic cell morphogenesis. Microtubule plus-end tracking proteins (+TIPs) transport polarity factors to the cell cortex, thereby playing a key role in both microtubule dynamics and cell polarity. However, the signalling pathway linking +TIPs to cell polarity control remains elusive. Here we show that the fission yeast checkpoint kinase Cds1 (Chk2 homologue) delays the transition of growth polarity from monopolar to bipolar (termed NETO; new-end take-off). The +TIPs CLIP170 homologue Tip1 and kinesin Tea2 are responsible for this delay, which is accompanied by a reduction in microtubule dynamics at the cell tip. Remarkably, microtubule stabilization occurs asymmetrically, prominently at the non-growing cell end, which induces abnormal accumulation of the polarity factor Tea1. Importantly, NETO delay requires activation of calcineurin, which is carried out by Cds1, resulting in Tip1 dephosphorylation. Thus, our study establishes a critical link between calcineurin and checkpoint-dependent cell morphogenesis.     

Phylogenetic relationships between Sophophora and Lordiphosa, with proposition of a hypothesis on the vicariant divergences of tropical lineages between the Old and New Worlds in the family Drosophilidae

Despite many studies on the phylogeny of the subgenus Sophophora, its monophyly has not been established, especially in relation to its putative relative, the genus Lordiphosa. We analyzed their phylogenetic relationships using DNA sequence data of two mitochondrial genes (ND2 and COII) and two nuclear genes (Adh and 28SrRNA). In constructing phylogenetic trees, we accounted for the problem of among-taxa nucleotide compositional heterogeneity, and took a sequence-partitioning approach to allow multiple substitution models for nucleotide sequences that have evolved under different evolutionary processes, particularly developing a novel, sequence-partitioning procedure for Neighbor Joining (NJ) tree construction. Trees constructed by different methods showed an almost identical and strongly supported topology in which Sophophora was paraphyletic: Lordiphosa was placed as the sister to the Neotropical Sophophora consisting of the saltans and willistoni groups, and Sophophora was divided into the clade of Lordiphosa+Neotropical Sophophora and the clade of the obscura+melanogaster groups. Based on the estimated time, 45.9 Mya, of divergence between the Old World Lordiphosa and the Neotropical Sophophora and evidence from paleontology, paleo-geography and -climatology, we propose a hypothesis that this vicariant divergence should have occurred when the North Atlantic Land Bridge between Europe and North America broke in the middle Eocene Epoch.     

Morphological changes in diabetic kidney are associated with increased <Emphasis Type="Italic">O</Emphasis>-GlcNAcylation of cytoskeletal proteins including α-actinin 4

Purpose  

The objective of the present study is to identify proteins that change in the extent of the modification with O-linked N-acetylglucosamine (O-GlcNAcylation) in the kidney from diabetic model Goto-Kakizaki (GK) rats, and to discuss the relation between O-GlcNAcylation and the pathological condition in diabetes.     

Eugregarine infection within the digestive tract of larval Antarctic krill, Euphausia superba

The infection rate of eugregarine parasites, Cephaloidophora pacifica, within the digestive tract of larval Antarctic krill, Euphausia superba, was examined using samples collected from the Indian sector of the Southern Ocean. Immature and mature eugregarine gamont stages were found at all larval stages older than Calyptopis I stage. Eugregarine infection in 14.0% (N = 108) of the first feeding stage (Calyptopis I) suggested that krill larvae are at risk from being infected during physiological transition from non-feeding to feeding stages. Eugregarine prevalence and intensity of infection at the three calyptopis stages increased with stage/krill length. Statistical analysis showed that the intensity of C. pacifica infection also increased with host density. Thus, krill density is probably a key determinant of the intensity of infection. We found gamont stage eugregarines in the host hind-gut, blocking the passage of food. Eugregarine infections in larval krill may have a negative impact on digestion and absorption in the host digestive tract.     

Isolation and characterization of a gene encoding a S-adenosyl-l-methionine-dependent halide/thiol methyltransferase (HTMT) from the marine diatom Phaeodactylum tricornutum: Biogenic mechanism of CH(3)I emissions in oceans

Several marine algae including diatoms exhibit S-adenosyl-l-methionine (SAM) halide/thiol methyltransferase (HTMT) activity, which is involved in the emission of methyl halides. In this study, the in vivo biogenic emission of methyl iodide from the diatom Phaeodactylum tricornutum was found to be clearly correlated with iodide concentration in the incubation media. The gene encoding HTMT (Pthtmt) was isolated from P. tricornutum CCAP 1055/1, and expressed in Escherichia coli. The molecular weight of the enzyme was 29.7kDa including a histidine tag, and the optimal pH was around pH 7.0. The kinetic properties of recombinant PtHTMT towards Cl(-), Br(-), I(-), [SH](-), [SCN](-), and SAM were 637.88mM, 72.83mM, 8.60mM, 9.92mM, 7.9mM, and 0.016mM, respectively, and were similar to those of higher-plant HTMTs, except that the activity towards thiocyanate was lower. The biogenic emission of methyl halides from the cultured cells and the enzymatic properties of HTMT suggest that the HMT/HTMT reaction is key to understanding the biogenesis of methyl halides in oceanic environments as well as terrestrial ones.