• BMB Reports
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• v.44 no.3
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• pp.147-157
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• 2011

The meiotic process from the primordial stage to zygote in female germ cells is mainly adjusted by post-transcriptional regulation of pre-existing maternal mRNA and post-translational modification of proteins. Several key proteins such as the cell cycle regulator, Cdk1/cyclin B, are post-translationally modified for precise control of meiotic progression. The second messenger (cAMP), kinases (PKA, Akt, MAPK, Aurora A, CaMK II, etc), phosphatases (Cdc25, Cdc14), and other proteins (G-protein coupled receptor, phosphodiesterase) are directly or indirectly involved in this process. Many proteins, such as CPEB, maskin, eIF4E, eIF4G, 4E-BP, and 4E-T, post-transcriptionally regulate mRNA via binding to the cap structure at the 5' end of mRNA or its 3' untranslated region (UTR) to generate a closed-loop structure. The 3' UTR of the transcript is also implicated in post-transcriptional regulation through an association with proteins such as CPEB, CPSF, GLD-2, PARN, and Dazl to modulate poly(A) tail length. RNA interfering is a new regulatory mechanism of the amount of mRNA in the mouse oocyte. This review summarizes information about post-transcriptional and post-translational regulation during mouse oocyte meiotic maturation.

• Journal of Life Science
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• v.24 no.10
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• pp.1144-1150
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• 2014

The eIF4E protein is the key regulator of translation initiation. The interaction of eIF4E with eIF4G triggers the translation of mRNA, and several proteins interrupt this association to modulate translation. Human 4E-T is one of the eIF4E-binding partners that represses the translation of bound mRNAs, and it is involved in the transport of eIF4E to processing bodies (P-bodies). Although Clast4, the mouse homolog of human 4E-T, might play critical roles in the regulation of translation, its properties are not well known. In this report, we deciphered the properties of Clast4 by determining its phosphorylation state, binding to eIF4E, and effects of overexpression on cell proliferation. Clast4 was phosphorylated by protein kinase A (PKA) in vivo on several residues of its amino terminus. Nevertheless, the PKA phosphorylation of Clast4 appeared to have no effect on either its eIF4E-binding ability or localization. Clast4 interacted with eIF4E1 and CPEB. The conserved eIF4E-binding sequence in Clast4, $YXXXXL_{\phi}$, was important for binding eIF4E1A but not eIF4E1B. Similar to that of another well-known eIF4E regulator, the eIF4E binding protein (4E-BP), the overexpression of Clast4 decreased cell proliferation. These results suggest that Clast4 acts as a global translation regulator in cells.

• Journal of Life Science
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• v.25 no.10
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• pp.1184-1195
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• 2015

The zebrafish is an emerging vertebrate model organism in reproductive biology. The oocyte maturation of zebrafish is triggered by maturation inducing hormone (MIH, 17α,20β-Dihydroxy-4-pregnen-3-one). In almost all animals, the oocyte maturation is governed by activation of pre-MPF which consists of cyclinB and inactive Cdk1. In the oocyte of Xenopus and mice, the activity of Cdk1 is regulated in two ways, one is the interaction with cyclinB and the other is phosphorylation/dephosphorylation of T14/Y15 residues on the Cdk1 by Wee1 and Cdc25. Unlike Xenopus and mice that have a sufficient amount of pre-MPF, pre-MPF is absent in GV oocyte of most teleost including zebrafish. Therefore, the activation of MPF during zebrafish oocyte maturation might totally depend on de novo synthesis of cyclinB proteins. It is reported that the translation of maternal mRNA is regulated by combination of several RNA binding proteins such as CPEB, Dazl, Pum1/Pum2, and insulin-like growth factor2 mRNA-binding protein 3 in the zebrafish oocytes. However, the definitive mechanism of these proteins to regulate the translation of stored maternal mRNAs remains to be elucidated. Therefore, the investigation of the maturation process of the zebrafish oocyte will provide new information that can help identify the role of translational control in early vertebrate oocyte maturation.

• Biomolecules & Therapeutics
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• v.14 no.2
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• pp.75-82
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• 2006

Synaptic plasticity, which is a long lasting change in synaptic efficacy, underlies many neural processes like learning and memory. It has long been acknowledged that new protein synthesis is essential for both the expression of synaptic plasticity and memory formation and storage. Most of the research interests in this field have focused on the events regulating transcriptional activation of gene expression from the cell body and nucleus. Considering extremely differentiated structural feature of a neuron in CNS, a neuron should meet a formidable task to overcome spatial and temporal restraints to deliver newly synthesized proteins to specific activated synapses among thousands of others, which are sometimes several millimeters away from the cell body. Recent advances in synaptic neurobiology has found that almost all the machinery required for the new protein translation are localized inside or at least in the vicinity of postsynaptic compartments. These findings led to the hypothesis that dormant mRNAs are translationally activated locally at the activated synapse, which may enable rapid and delicate control of new protein synthesis at activated synapses. In this review, we will describe the mechanism of local translational control at activated synapses focusing on the role of cytoplasmic polyadenylation of dormant mRNAs.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.4
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• pp.462-469
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• 2017

Objective: The aim of this study is to identify genomic regions or genes controlling growth traits in pigs. Methods: Using a panel of 54,148 single nucleotide polymorphisms (SNPs), we performed a genome-wide Association (GWA) study in 562 pure Yorshire pigs with four growth traits: average daily gain from 30 kg to 100 kg or 115 kg, and days to 100 kg or 115 kg. Fixed and random model Circulating Probability Unification method was used to identify the associations between 54,148 SNPs and these four traits. SNP annotations were performed through the Sus scrofa data set from Ensembl. Bioinformatics analysis, including gene ontology analysis, pathway analysis and network analysis, was used to identify the candidate genes. Results: We detected 6 significant and 12 suggestive SNPs, and identified 9 candidate genes in close proximity to them (suppressor of glucose by autophagy [SOGA1], R-Spondin 2 [RSPO2], mitogen activated protein kinase kinase 6 [MAP2K6], phospholipase C beta 1 [PLCB1], rho GTPASE activating protein 24 [ARHGAP24], cytoplasmic polyadenylation element binding protein 4 [CPEB4], GLI family zinc finger 2 [GLI2], neuronal tyrosine-phosphorylated phosphoinositide-3-kinase adaptor 2 [NYAP2], and zinc finger protein multitype 2 [ZFPM2]). Gene ontology analysis and literature mining indicated that the candidate genes are involved in bone, muscle, fat, and lung development. Pathway analysis revealed that PLCB1 and MAP2K6 participate in the gonadotropin signaling pathway and suggests that these two genes contribute to growth at the onset of puberty. Conclusion: Our results provide new clues for understanding the genetic mechanisms underlying growth traits, and may help improve these traits in future breeding programs.