title: Hippo signaling components, Mst1 and Mst2, act as a switch between self-renewal and differentiation in Xenopus hematopoietic and endothelial progenitors.
abstract: Hippo signaling is a conserved pathway that regulates cell proliferation and organ size control. Mst1 and Mst2 were identified as homologs of hippo and as core kinases of the Hippo pathway in mammals. Here, we have characterized the role of Mst1 and Mst2 during Xenopus primitive hematopoiesis. We showed that Mst1 and Mst2 were strongly expressed in the Xenopus ventral blood island, where primitive hematopoiesis is initiated. Loss-of-function analysis of Mst1/2 revealed morphogenetic defects, including short axis, smaller eyes and abnormal epidermis, and decreased phosphorylation of Yap. Mst1/2 morphants did not exhibit any change in the expression of hematopoietic and endothelial progenitor markers in early hematopoietic development. In addition, we have shown that such progenitor markers were continuously expressed through to the late hematopoietic development stage. As a result, the expression of erythroid, myeloid and endothelial differentiation markers were decreased in Mst1/2 morphants. Our results indicate that Mst1/2 act as a differentiation switch in Xenopus hematopoietc and endothelial progenitors.
authors.affiliation: Department of Life Sciences (Biology), Graduate School of Arts and Sciences, The University of Tokyo, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Nejigane
authors.forename: Shuji
authors.initials: S
authors.lastname: Takahashi
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Haramoto
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Michiue
authors.forename: Makoto
authors.initials: M
authors.lastname: Asashima
mesh_terms: D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D004625:Embryo, Nonmammalian / Q000098:blood supply / Q000196:embryology / Q000378:metabolism; D004727:Endothelium / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D006413:Hematopoietic System / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000090742:Serine-Threonine Kinase 3; D015398:Signal Transduction / Q000235:genetics*; D013234:Stem Cells / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014981:Xenopus / Q000196:embryology / Q000235:genetics*; D029867:Xenopus Proteins / Q000235:genetics* / Q000378:metabolism; D000091102:YAP-Signaling Proteins; D000099317:Hippo Kinases
chemical_list: D017346:Protein Serine-Threonine Kinases; D000090742:Serine-Threonine Kinase 3; D015534:Trans-Activators; D029867:Xenopus Proteins; D000091102:YAP-Signaling Proteins; C561677:YAP protein, Xenopus; C586461:Mst1 protein, Xenopus; D000099317:Hippo Kinases; C586462:STK3 protein, Xenopus