title: CDK phosphorylation of SLD-2 is required for replication initiation and germline development in C. elegans.
abstract: Cyclin-dependent kinase (CDK) plays a vital role in proliferation control across eukaryotes. Despite this, how CDK mediates cell cycle and developmental transitions in metazoa is poorly understood. In this paper, we identify orthologues of Sld2, a CDK target that is important for DNA replication in yeast, and characterize SLD-2 in the nematode worm Caenorhabditis elegans. We demonstrate that SLD-2 is required for replication initiation and the nuclear retention of a critical component of the replicative helicase CDC-45 in embryos. SLD-2 is a CDK target in vivo, and phosphorylation regulates the interaction with another replication factor, MUS-101. By mutation of the CDK sites in sld-2, we show that CDK phosphorylation of SLD-2 is essential in C. elegans. Finally, using a phosphomimicking sld-2 mutant, we demonstrate that timely CDK phosphorylation of SLD-2 is an important control mechanism to allow normal proliferation in the germline. These results determine an essential function of CDK in metazoa and identify a developmental role for regulated SLD-2 phosphorylation.
authors.affiliation: Wellcome Trust/Cancer Research UK Gurdon Institute, 2 Department of Genetics, and 3 Department of Zoology, University of Cambridge, Cambridge CB2 1QN, England, UK.
authors.forename: Vincent
authors.initials: V
authors.lastname: Gaggioli
authors.forename: Eva
authors.initials: E
authors.lastname: Zeiser
authors.forename: David
authors.initials: D
authors.lastname: Rivers
authors.forename: Charles R
authors.initials: CR
authors.lastname: Bradshaw
authors.forename: Julie
authors.initials: J
authors.lastname: Ahringer
authors.forename: Philip
authors.initials: P
authors.lastname: Zegerman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D018507:Gene Expression Regulation, Developmental; D005854:Germ Cells / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D017386:Sequence Homology, Amino Acid; D019076:Transgenes / Q000502:physiology
chemical_list: D029742:Caenorhabditis elegans Proteins; D018844:Cyclin-Dependent Kinases