Background: Archaea form a third domain of life that is distinct from Bacteria and Eukarya. So far, many scholars have elucidated considerable details about the typical promoter architectures of the three domains of life. However, a functional promoter from the archaeon Halobacterium salinarum has never been studied in Escherichia coli.
View Article and Find Full Text PDFUnlabelled: Heterochromatin Protein 1 (HP1) is a conserved chromosomal protein in eukaryotic cells that has a major role in directing heterochromatin formation, a process that requires co-transcriptional gene silencing mediated by small RNAs and their associated argonaute proteins. Heterochromatin formation requires erasing the active epigenetic mark, such as H3K4me2, but the molecular link between HP1 and H3K4 demethylation remains unclear. In a fertility screen in female , we identified (), which functions in the stem cell niche, downstream of Piwi, to support germline stem cell differentiation.
View Article and Find Full Text PDFTubular sclerosis complex gene products TSC1 and TSC2 have evolutionarily conserved roles in cell growth from Drosophila to mammals. Here we reveal important roles for TSC1/2 in regulating intestinal stem cell (ISC) maintenance and differentiation of the enteroendocrine cell lineage in the Drosophila midgut. Loss of either the Tsc1 or Tsc2 gene in ISCs causes rapid ISC loss through TORC1 hyperactivation, because ISCs can be efficiently rescued by mutation of S6k or by rapamycin treatment.
View Article and Find Full Text PDFAdenomatous polyposis coli (APC) and K-ras are the two most frequently mutated genes found in human colorectal cancers. In human colorectal cancers, Wnt signaling activation after the loss of APC is hypothesized to be the key event for adenoma initiation, whereas additional mutations such as Ras activation are required for the progression from adenoma to carcinoma. However, accumulating data have led to conflicting views regarding the precise role of Ras in APC loss-induced tumorigenesis.
View Article and Find Full Text PDFBackground: The p55 family WD40 repeat-containing histone chaperone proteins are components of several chromatin regulatory complexes (such as PRC2, NURF and CAF-1) and interact with histone H4, yet their functional relevance in vivo is unclear.
Results: Here we use Drosophila as a genetic model to dissect the function of p55/Caf1 during development. In agree with a recent report, we find that p55 is essential for Drosophila development and is required for cell proliferation and viability.
Tuberous sclerosis complex human disease gene products TSC1 and TSC2 form a functional complex that negatively regulates target of rapamycin (TOR), an evolutionarily conserved kinase that plays a central role in cell growth and metabolism. Here, we describe a novel role of TSC1/2 in controlling stem cell maintenance. We show that in the Drosophila ovary, disruption of either the Tsc1 or Tsc2 gene in germline stem cells (GSCs) leads to precocious GSC differentiation and loss.
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