Global Transcriptional Repression in C. Elegans Germline Precursors by Regulated Sequestration of TAF-4
Overview
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In C. elegans, four asymmetric divisions, beginning with the zygote (P0), generate transcriptionally repressed germline blastomeres (P1-P4) and somatic sisters that become transcriptionally active. The protein PIE-1 represses transcription in the later germline blastomeres but not in the earlier germline blastomeres P0 and P1. We show here that OMA-1 and OMA-2, previously shown to regulate oocyte maturation, repress transcription in P0 and P1 by binding to and sequestering in the cytoplasm TAF-4, a component critical for assembly of TFIID and the pol II preinitiation complex. OMA-1/2 binding to TAF-4 is developmentally regulated, requiring phosphorylation by the DYRK kinase MBK-2, which is activated at meiosis II after fertilization. OMA-1/2 are normally degraded after the first mitosis, but ectopic expression of wild-type OMA-1 is sufficient to repress transcription in both somatic and later germline blastomeres. We propose that phosphorylation by MBK-2 serves as a developmental switch, converting OMA-1/2 from oocyte to embryo regulators.
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Bloom J, Green R, Desai A, Oegema K, Rifkin S bioRxiv. 2024; .
PMID: 39484375 PMC: 11526918. DOI: 10.1101/2024.10.19.619171.
The TOP-2/condensin II axis silences transcription during germline specification in C. elegans.
Belew M, Chien E, Wong M, Michael W G3 (Bethesda). 2024; .
PMID: 39358855 PMC: 11631511. DOI: 10.1093/g3journal/jkae236.
Protein profiling of zebrafish embryos unmasks regulatory layers during early embryogenesis.
da Silva Pescador G, Baia Amaral D, Varberg J, Zhang Y, Hao Y, Florens L Cell Rep. 2024; 43(10):114769.
PMID: 39302832 PMC: 11544563. DOI: 10.1016/j.celrep.2024.114769.
Connors C, Mauro M, Wiles J, Countryman A, Martin S, Lacroix B Mol Biol Cell. 2024; 35(7):ar94.
PMID: 38696255 PMC: 11244169. DOI: 10.1091/mbc.E24-02-0096-T.
Mechanisms of lineage specification in Caenorhabditis elegans.
Liu J, Murray J Genetics. 2023; 225(4).
PMID: 37847877 PMC: 11491538. DOI: 10.1093/genetics/iyad174.