RRC ID 29104
Author Choi CH, Thomason PA, Zaki M, Insall RH, Barber DL.
Title Phosphorylation of actin-related protein 2 (Arp2) is required for normal development and cAMP chemotaxis in Dictyostelium.
Journal J Biol Chem
Abstract Phosphorylation of the actin-related protein 2 (Arp2) subunit of the Arp2/3 complex on evolutionarily conserved threonine and tyrosine residues was recently identified and shown to be necessary for nucleating activity of the Arp2/3 complex and membrane protrusion of Drosophila cells. Here we use the Dictyostelium diploid system to replace the essential Arp2 protein with mutants that cannot be phosphorylated at Thr-235/6 and Tyr-200. We found that aggregation of the resulting mutant cells after starvation was substantially slowed with delayed early developmental gene expression and that chemotaxis toward a cAMP gradient was defective with loss of polarity and attenuated F-actin assembly. Chemotaxis toward cAMP was also diminished with reduced cell speed and directionality and shorter pseudopod lifetime when Arp2 phosphorylation mutant cells were allowed to develop longer to a responsive state similar to that of wild-type cells. However, clathrin-mediated endocytosis and chemotaxis under agar to folate in vegetative cells were only subtly affected in Arp2 phosphorylation mutants. Thus, phosphorylation of threonine and tyrosine is important for a subset of the functions of the Arp2/3 complex, in particular an unexpected major role in regulating development.
Volume 288(4)
Pages 2464-74
Published 2013-1-25
DOI 10.1074/jbc.M112.435313
PII M112.435313
PMID 23223240
PMC PMC3554915
MeSH Actin Cytoskeleton / metabolism Actin-Related Protein 2 / chemistry* Actins / metabolism Alleles Animals Cell Movement Chemotaxis Cyclic AMP / metabolism* Dictyostelium / metabolism* Endocytosis Models, Biological Mutation Phosphorylation Spectroscopy, Fourier Transform Infrared / methods Tyrosine / chemistry
IF 4.106
Times Cited 13
Cellular slime molds S90278