RRC ID 33170
Author Hamada-Kawaguchi N, Nishida Y, Yamamoto D.
Title Btk29A-mediated tyrosine phosphorylation of armadillo/β-catenin promotes ring canal growth in Drosophila oogenesis.
Journal PLoS One
Abstract Drosophila Btk29A is the ortholog of mammalian Btk, a Tec family nonreceptor tyrosine kinase whose deficit causes X-linked agammaglobulinemia in humans. The Btk29AficP mutation induces multiple abnormalities in oogenesis, including the growth arrest of ring canals, large intercellular bridges that allow the flow of cytoplasm carrying maternal products essential for embryonic development from the nurse cells to the oocyte during oogenesis. In this study, inactivation of Parcas, a negative regulator of Btk29A, was found to promote Btk29A accumulation on ring canals with a concomitant increase in the ring canal diameter, counteracting the Btk29AficP mutation. This mutation markedly reduced the accumulation of phosphotyrosine on ring canals and in the regions of cell-cell contact, where adhesion-supporting proteins such as DE-cadherin and β-catenin ortholog Armadillo (Arm) are located. Our previous in vitro and in vivo analyses revealed that Btk29A directly phosphorylates Arm, leading to its release from DE-cadherin. In the present experiments, immunohistological analysis revealed that phosphorylation at tyrosine 150 (Y150) and Y667 of Arm was diminished in Btk29AficP mutant ring canals. Overexpression of an Arm mutant with unphosphorylatable Y150 inhibited ring canal growth. Thus Btk29A-induced Y150 phosphorylation is necessary for the normal growth of ring canals. We suggest that the dissociation of tyrosine-phosphorylated Arm from DE-cadherin allows dynamic actin to reorganize, leading to ring canal expansion and cell shape changes during the course of oogenesis.
Volume 10(3)
Pages e0121484
Published 2015-3-24
DOI 10.1371/journal.pone.0121484
PII PONE-D-14-57902
PMID 25803041
PMC PMC4372500
MeSH Actins / metabolism Animals Armadillo Domain Proteins / chemistry* Armadillo Domain Proteins / metabolism* Drosophila Proteins / chemistry* Drosophila Proteins / metabolism* Drosophila melanogaster / cytology Drosophila melanogaster / embryology* Drosophila melanogaster / metabolism Extracellular Space / metabolism* Intracellular Space / metabolism Oogenesis* Phosphorylation Protein Transport Protein-Tyrosine Kinases / metabolism* Transcription Factors / chemistry* Transcription Factors / metabolism* Tyrosine / metabolism*
IF 2.74
Times Cited 7