kin-19/casein kinase Iα has dual functions in regulating asymmetric division and terminal differentiation in C. elegans epidermal stem cells.
Casein Kinase I (CKI) is a conserved component of the Wnt signaling pathway, which regulates cell fate determination in metazoans. We show that post-embryonic asymmetric division and fate specification of C. elegans epidermal stem cells are controlled by a non-canonical Wnt/β-catenin signaling pathway, involving the β-catenins WRM-1 and SYS-1, and that C. elegans kin-19/CKIα functions in this pathway. Furthermore, we find that kin-19 is the only member of the Wnt asymmetry pathway that functions with, or in parallel to, the heterochronic temporal patterning pathway to control withdrawal from self-renewal and subsequent terminal differentiation of epidermal stem cells. We show that, except in the case of kin-19, the Wnt asymmetry pathway and the heterochronic pathway function separately and in parallel to control different aspects of epidermal stem cell fate specification. However, given the function of kin-19/CKIα in both pathways, and that CKI, Wnt signaling pathway and heterochronic pathway genes are widely conserved in animals, our findings suggest that CKIα may function as a regulatory hub through which asymmetric division and terminal differentiation are coordinated in adult stem cells of vertebrates.
Department of Biological Sciences, Virginia Tech University, Blacksburg, VA, USA. dibaner@vt.edu
Diya
D
Banerjee
Xin
X
Chen
Shin Yi
SY
Lin
Frank J
FJ
Slack
D000818:Animals; D017173:Caenorhabditis elegans / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D048128:Casein Kinase Ialpha / Q000378:metabolism / Q000502:physiology*; D002454:Cell Differentiation; D002455:Cell Division; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D000078404:Epidermal Cells; D055785:Gene Knockdown Techniques; D007814:Larva / Q000201:enzymology; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D034622:RNA Interference; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology / Q000201:enzymology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D051153:Wnt Proteins / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; D003598:Cytoskeletal Proteins; C502083:Sys-1 protein, C elegans; D014157:Transcription Factors; C120104:WRM-1 protein, C elegans; D051153:Wnt Proteins; D051176:beta Catenin; D011494:Protein Kinases; D048128:Casein Kinase Ialpha; C508382:KIN-19 protein, C elegans