Essential role for Abi1 in embryonic survival and WAVE2 complex integrity Journal Article


Authors: Dubielecka, P. M.; Ladwein, K. I.; Xiong, X.; Migeotte, I.; Chorzalska, A.; Anderson, K. V.; Sawicki, J. A.; Rottner, K.; Stradal, T. E.; Kotula, L.
Article Title: Essential role for Abi1 in embryonic survival and WAVE2 complex integrity
Abstract: Abl interactor 1 (Abi1) plays a critical function in actin cytoskeleton dynamics through participation in the WAVE2 complex. To gain a better understanding of the specific role of Abi1, we generated a conditional Abi1-KO mouse model and MEFs lacking Abi1 expression. Abi1-KO cells displayed defective regulation of the actin cytoskeleton, and this dysregulation was ascribed to altered activity of the WAVE2 complex. Changes in motility of Abi1-KO cells were manifested by a decreased migration rate and distance but increased directional persistence. Although these phenotypes did not correlate with peripheral ruffling, which was unaffected, Abi1-KO cells exhibited decreased dorsal ruffling. Western blotting analysis of Abi1-KO cell lysates indicated reduced levels of the WAVE complex components WAVE1 and WAVE2, Nap1, and Sra-1/PIR121. Although relative Abi2 levels were more than doubled in Abi1-KO cells, the absolute Abi2 expression in these cells amounted only to a fifth of Abi1 levels in the control cell line. This finding suggests that the presence of Abi1 is critical for the integrity and stability of WAVE complex and that Abi2 levels are not sufficiently increased to compensate fully for the loss of Abi1 in KO cells and to restore the integrity and function of the WAVE complex. The essential function of Abi1 in WAVE complexes and their regulation might explain the observed embryonic lethality of Abi1-deficient embryos, which survived until approximately embryonic day 11.5 and displayed malformations in the developing heart and brain. Cells lacking Abi1 and the conditional Abi1-KO mouse will serve as critical models for defining Abi1 function.
Keywords: protein expression; unclassified drug; nonhuman; protein function; animal cell; mouse; phenotype; actin; embryo; protein; protein stability; embryo development; western blotting; cell migration; cytoskeleton; cell motility; congenital heart malformation; knockout mouse; brain malformation; cell lysate; lamellipodium; embryo death; arp2/3-complex; hssh3bp1; rac; abi1 protein; abi2 protein; nucleosome assembly protein 1; sra 1 protein; wave1 protein; wave2 protein
Journal Title: Proceedings of the National Academy of Sciences of the United States of America
Volume: 108
Issue: 17
ISSN: 0027-8424
Publisher: National Academy of Sciences  
Date Published: 2011-04-26
Start Page: 7022
End Page: 7027
Language: English
DOI: 10.1073/pnas.1016811108
PROVIDER: scopus
PMCID: PMC3084068
PUBMED: 21482783
DOI/URL:
Notes: --- - "Export Date: 23 June 2011" - "CODEN: PNASA" - "Source: Scopus"
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  1. Kathryn Anderson
    148 Anderson