HSPC300 and its role in neuronal connectivity.
BACKGROUND
The WAVE/SCAR complex, consisting of CYFIP (PIR121 or Sra1), Kette (Nap1), Abi, SCAR (WAVE) and HSPC300, is known to regulate the actin nucleating Arp2/3 complex in a Rac1-dependent manner. While in vitro and in vivo studies have demonstrated that CYFIP, Kette, Abi and SCAR work as subunits of the complex, the role of the small protein HSPC300 remains unclear.


RESULTS
In the present study, we identify the HSPC300 gene and characterize its interaction with the WAVE/SCAR complex in the Drosophila animal model. On the basis of several lines of evidence, we demonstrate that HSPC300 is an indispensable component of the complex controlling axonal and neuromuscular junction (NMJ) growth. First, the Drosophila HSPC300 expression profile resembles that of other members of the WAVE/SCAR complex. Second, HSPC300 mutation, as well as mutations in the other complex subunits, results in identical axonal and NMJ growth defects. Third, like with other complex subunits, defects in NMJ architecture are rescued by presynaptic expression of the respective wild-type gene. Fourth, HSPC300 genetically interacts with another subunit of the WAVE/SCAR complex. Fifth, HSPC300 physically associates with CYFIP and SCAR.


CONCLUSIONS
Present data provide the first evidence for HSPC300 playing a role in nervous system development and demonstrate in vivo that this small protein works in the context of the WAVE/SCAR complex.
Qurashi
Abrar
A
Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, BP 10142, 67404 Illkirch, CU de Strasbourg, France. qurashi.abrar@gmail.com
Sahin
H Bahar
HB
Carrera
Pilar
P
Gautreau
Alexis
A
Schenck
Annette
A
Giangrande
Angela
A
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004331:Drosophila melanogaster; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D009046:Motor Neurons / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D009420:Nervous System / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D009434:Neural Pathways / Q000254:growth & development / Q000378:metabolism; D009469:Neuromuscular Junction / Q000254:growth & development* / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000235:genetics / Q000378:metabolism*
C121808:Abi protein, Drosophila; D048868:Adaptor Proteins, Signal Transducing; C519848:BRK1 protein, human; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; C533257:HSPC300 protein, Drosophila; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D021122:Protein Subunits; C484666:Sra-1 protein, Drosophila; D051300:Wiskott-Aldrich Syndrome Protein Family; C478569:hem protein, Drosophila