AIP1/WDR1 supports mitotic cell rounding.
The actin cytoskeleton plays a fundamental role in configuring cell shapes and movements. Actin interacting protein 1 (AIP1)/tryptophan-aspartate-repeat protein 1 (WDR1) induces actin severing and disassembly cooperating with ADF/cofilin. We found that mitotic cell flattening but not rounding was manifested by suppression of AIP1/WDR1 in cells. This mitotic cell flattening was not due to any changes in phosphorylation and distribution of cofilin in cells. We carried out a direct observation of actin filament severing/disassembly assay and found that phosphorylated cofilin still somewhat severs/disassembles actin filaments and that AIP1/WDR1 effaces this in vitro. We suggest that the phosphorylation of ADF/cofilin will be insufficient to completely inhibit actin turnover during mitosis, and that AIP1/WDR1 could abort the severing/disassembly activity somewhat still carried out due to phosphorylated ADF/cofilin. This mechanism could be required to induce cell morphologic changes, especially mitotic cell rounding.
Fujibuchi
Taketsugu
T
Division of Molecular Pathology, Department of Pathology, National University Corporation, Ehime University School of Medicine, Toh-on, Ehime 791-0295, Japan.
Abe
Yasuhito
Y
Takeuchi
Takashi
T
Imai
Yoshinori
Y
Kamei
Yoshiaki
Y
Murase
Ryuichi
R
Ueda
Norifumi
N
Shigemoto
Kazuhiro
K
Yamamoto
Haruyasu
H
Kito
Katsumi
K
D051339:Actin Depolymerizing Factors; D000199:Actins / Q000378:metabolism; D002453:Cell Cycle; D045744:Cell Line, Tumor; D048430:Cell Shape; D020090:Chromosome Segregation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation; D006801:Humans; D008840:Microfilament Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008938:Mitosis; D010766:Phosphorylation; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000378:metabolism
D051339:Actin Depolymerizing Factors; D000199:Actins; D004791:Enzyme Inhibitors; D008840:Microfilament Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C118067:WDR1 protein, human; D020742:rhoA GTP-Binding Protein