Publication Date:
2008-01-18
Description:
Germ cells are the only cells that transmit genetic information to the next generation, and they therefore must be prevented from differentiating inappropriately into somatic cells. A common mechanism by which germline progenitors are protected from differentiation-inducing signals is a transient and global repression of RNA polymerase II (RNAPII)-dependent transcription. In both Drosophila and Caenorhabditis elegans embryos, the repression of messenger RNA transcription during germ cell specification correlates with an absence of phosphorylation of Ser 2 residues in the carboxy-terminal domain of RNAPII (hereafter called CTD), a critical modification for transcriptional elongation. Here we show that, in Drosophila embryos, a small protein encoded by polar granule component (pgc) is essential for repressing CTD Ser 2 phosphorylation in newly formed pole cells, the germline progenitors. Ectopic Pgc expression in somatic cells is sufficient to repress CTD Ser 2 phosphorylation. Furthermore, Pgc interacts, physically and genetically, with positive transcription elongation factor b (P-TEFb), the CTD Ser 2 kinase complex, and prevents its recruitment to transcription sites. These results indicate that Pgc is a cell-type-specific P-TEFb inhibitor that has a fundamental role in Drosophila germ cell specification. In C. elegans embryos, PIE-1 protein segregates to germline blastomeres, and is thought to repress mRNA transcription through interaction with P-TEFb. Thus, inhibition of P-TEFb is probably a common mechanism during germ cell specification in the disparate organisms C. elegans and Drosophila.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2719856/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2719856/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hanyu-Nakamura, Kazuko -- Sonobe-Nojima, Hiroko -- Tanigawa, Akie -- Lasko, Paul -- Nakamura, Akira -- R01 HD036631/HD/NICHD NIH HHS/ -- R01 HD036631-10/HD/NICHD NIH HHS/ -- England -- Nature. 2008 Feb 7;451(7179):730-3. doi: 10.1038/nature06498. Epub 2008 Jan 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory for Germline Development, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18200011" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Caenorhabditis elegans
;
Cell Line
;
Chromatin/genetics/*metabolism
;
Drosophila Proteins/genetics/*metabolism
;
Drosophila melanogaster/*cytology/embryology/genetics/*metabolism
;
Gene Expression Regulation, Developmental
;
Germ Cells/cytology/*metabolism
;
Phosphorylation
;
Phosphoserine/metabolism
;
Positive Transcriptional Elongation Factor B/antagonists &
;
inhibitors/genetics/*metabolism
;
Protein Binding
;
Protein Structure, Tertiary
;
RNA Polymerase II/chemistry/metabolism
;
Stem Cells/cytology/metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
