Abi activates WASP to promote sensory organ development.
Actin polymerization is a key process for many cellular events during development. To a large extent, the formation of filamentous actin is controlled by the WASP and WAVE proteins that activate the Arp2/3 complex in different developmental processes. WAVE function is regulated through a protein complex containing Sra1, Kette and Abi. Using biochemical, cell biological and genetic tools, we show here that the Abi protein also has a central role in activating WASP-mediated processes. Abi binds WASP through its carboxy-terminal domain and acts as a potent stimulator of WASP-dependent F-actin formation. To elucidate the biological function of abi in Drosophila melanogaster, we studied bristle development, a process known to require wasp function. Reduction of abi function leads to a loss of bristles similar to that observed in wasp mutants. Activation of Abi results in the formation of ectopic bristles, a phenotype that is suppressed by a reduction of wasp activity but is not affected by the reduction of wave function. Thus, in vivo Abi may set the balance between WASP and WAVE in different actin-based developmental processes.
Bogdan
Sven
S
Institut für Neurobiologie, Universität Münster, Badestr. 9, D-48149 Münster, Germany.
Stephan
Raiko
R
Löbke
Christian
C
Mertens
Alexandra
A
Klämbt
Christian
C
D000199:Actins / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D004330:Drosophila / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012679:Sense Organs / Q000196:embryology* / Q000378:metabolism; D013997:Time Factors; D020798:Two-Hybrid System Techniques; D051316:Wiskott-Aldrich Syndrome Protein / Q000378:metabolism*; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000378:metabolism / Q000502:physiology
C121808:Abi protein, Drosophila; D000199:Actins; D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D029721:Drosophila Proteins; D008840:Microfilament Proteins; C484666:Sra-1 protein, Drosophila; C477859:WASp protein, Drosophila; D051316:Wiskott-Aldrich Syndrome Protein; D051300:Wiskott-Aldrich Syndrome Protein Family; C478569:hem protein, Drosophila