The expanding family of CREB/CREM transcription factors that are involved with spermatogenesis.

摘要: Abstract One of the molecular mechanisms shown to have played a major role in orchestrating expression many genes with unique cellular and temporal specificity spermatogenesis, is cAMP-dependent signaling pathway. In this pathway, gene mediated primarily by two members bZIP transcription factors—cAMP-response element binding protein (CREB) cAMP-responsive modulator (CREM). Both bind specific cis element, cAMP-response (CRE), promoter target genes, both are activated kinase A (PKA) phosphorylation that enables CREB (CBP) recruitment basal machinery, characterized multiple alternatively spliced forms. Some these forms lack transactivation domains hence function as suppressors. Sertoli cells, levels fluctuate cyclical manner depends on cell associations along spermatogenic wave. Follicle stimulating hormone (FSH) activates cAMP pathway consequently, positively auto-regulates its own (by CRE like promoter). Subsequently, essential for proper germ differentiation. addition, TNFα secreted round spermatids, NF-κB dependent cells thus, contributes elevated long intimately associated. Inducible early repressor (ICER), suppressor isoform CREM, also CREB, down regulates together expression, resetting level new antagonist CREM (α, β γ) present premeiotic prophase spermatocytes. prominent switch CREMτ CREMθ activating starts pachytene spermatocytes leading activation haploid important spermiogenesis spermatids. Interestingly, exerts independent state. It associates activator testis (ACT), has an intrinsic transcriptional activity, rather than CBP. These other findings suggest expanding CREB/CREM proteins potentially family key regulators at all stages spermatogenesis.