First published online February 24, 2006
Development 133, 602e (2006)
© The Company of Biologists Limited
BRICKing up actin nucleation
The nucleation of actin filaments by the Arp2/3 complex, which can be
activated by Scar/WAVE, is essential for many eukaryotic cellular processes,
including cell migration in animals and plant epidermal cell morphogenesis.
Genetic studies in Arabidopsis have revealed the functions of several
conserved components of a Scar/WAVE regulatory complex during trichome
(epidermal hair) formation. Now, Djakovic and colleagues report that BRICK1
(BRK1), the plant homolog of the mammalian Scar/WAVE complex component
HSPC300, regulates epidermal cell shape in Arabidopsis in concert
with SCAR and the ARP2/3 complex (see p.
1091). The researchers
show that mutations in BRK1 cause similar morphological defects in
trichomes and other epidermal cells to those caused by mutations that disrupt
the ARP2/3 complex. Epidermal defects in plants containing mutations in both
BRK1 and ARP2/3 components are no more extreme than those in single mutants,
indicating that BRK1 acts within the ARP2/3 pathway. Finally, the researchers
show that BRK1 protects SCAR1 protein from degradation, which may explain how
BRK1 controls ARP2/3 complex activity.
Related articles in Development:
- BRICK1/HSPC300 functions with SCAR and the ARP2/3 complex to regulate epidermal cell shape in Arabidopsis
- Stevan Djakovic, Julia Dyachok, Michael Burke, Mary J. Frank, and Laurie G. Smith
Development 2006 133: 1091-1100.
[Abstract]
[Full Text]