title: Drosophila sticky/citron kinase is a regulator of cell-cycle progression, genetically interacts with Argonaute 1 and modulates epigenetic gene silencing.
abstract: The sticky/citron kinase protein is a conserved regulator of cell-cycle progression from invertebrates to humans. While this kinase is essential for completion of cytokinesis, sticky/citron kinase phenotypes disrupting neurogenesis and cell differentiation suggest additional non-cell-cycle functions. However, it is not known whether these phenotypes are an indirect consequence of sticky mutant cell-cycle defects or whether they define a novel function for this kinase. We have isolated a temperature-sensitive allele of the Drosophila sticky gene and we show that sticky/citron kinase is required for histone H3-K9 methylation, HP1 localization, and heterochromatin-mediated gene silencing. sticky genetically interacts with Argonaute 1 and sticky mutants exhibit context-dependent Su(var) and E(var) activity. These observations indicate that sticky/citron kinase functions to regulate both actin-myosin-mediated cytokinesis and epigenetic gene silencing, possibly linking cell-cycle progression to heterochromatin assembly and inheritance of gene expression states.
authors.affiliation: Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Sweeney
authors.forename: Paula
authors.initials: P
authors.lastname: Campbell
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bosco
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D060565:Argonaute Proteins; D002453:Cell Cycle; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000166:cytology* / Q000201:enzymology* / Q000235:genetics; D039642:Eukaryotic Initiation Factors; D005123:Eye / Q000166:cytology / Q000648:ultrastructure; D005260:Female; D020868:Gene Silencing; D017344:Genes, Insect; D006570:Heterochromatin / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics*; D008745:Methylation; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D006080:Ovarian Follicle / Q000166:cytology; D011003:Ploidies; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics*; D013696:Temperature
chemical_list: C489654:AGO1 protein, Drosophila; D060565:Argonaute Proteins; D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; D039642:Eukaryotic Initiation Factors; D006570:Heterochromatin; D006657:Histones; D047908:Intracellular Signaling Peptides and Proteins; D000090266:Chromobox Protein Homolog 5; C115635:citron-kinase; D017346:Protein Serine-Threonine Kinases