title: Rab13 small G protein and junctional Rab13-binding protein (JRAB) orchestrate actin cytoskeletal organization during epithelial junctional development.
abstract: During epithelial junctional development, both vesicle transport and reorganization of the actin cytoskeleton must be spatiotemporally regulated. Coordination of these cellular functions is especially important, but the precise mechanism remains elusive. Previously, we identified junctional Rab13-binding protein (JRAB)/molecules interacting with CasL-like 2 (MICAL-L2) as an effector of the Rab13 small G protein, and we found that the Rab13-JRAB system may be involved in the formation of cell-cell adhesions via transport of adhesion molecules. Here, we showed that JRAB interacts with two actin-binding proteins, actinin-1 and -4, and filamentous actin via different domains and regulates actin cross-linking and stabilization through these interactions. During epithelial junctional development, JRAB is prominently enriched in the actin bundle at the free border; subsequently, JRAB undergoes a Rab13-dependent conformational change that is required for maturation of cell-cell adhesion sites. These results suggest that Rab13 and JRAB regulate reorganization of the actin cytoskeleton throughout epithelial junctional development from establishment to maturation of cell-cell adhesion.
authors.affiliation: Department of Biochemistry, Institute of Health Biosciences, Graduate School, Faculty of Medicine, University of Tokushima , Tokushima, Japan.
authors.forename: Ayuko
authors.initials: A
authors.lastname: Sakane
authors.forename: Ahmed Alamir Mahmoud
authors.initials: AA
authors.lastname: Abdallah
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Nakano
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Honda
authors.forename: Wataru
authors.initials: W
authors.lastname: Ikeda
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nishikawa
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Natsuki
authors.initials: N
authors.lastname: Matsushita
authors.forename: Toshio
authors.initials: T
authors.lastname: Kitamura
authors.forename: Takuya
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000185:Actinin / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D004848:Epithelium / Q000254:growth & development* / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008840:Microfilament Proteins; D008954:Models, Biological; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D019108:Tight Junctions / Q000378:metabolism*; D020691:rab GTP-Binding Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; C512298:JRAB protein, mouse; D008840:Microfilament Proteins; D000185:Actinin; D020691:rab GTP-Binding Proteins