|Allwood, E. G.,
Smertenko, A. P. & Hussey, P. J. (2001) Phosphorylation of plant
actin-depolymerising factor by calmodulin-like domain protein kinase. FEBS
letters. 499, 97-100.
|The actin-depolymerising factor
(ADF)/cofilin group of proteins are stimulus-responsive actin-severing
proteins, members of which are regulated by reversible phosphorylation.
The phosphorylation site on the maize ADF, ZmADF3, is Ser-6 but the
kinase responsible is unknown [Smertenko et al., Plant J. 14 (1998)
187-193]. We have partially purified the ADF kinase(s) and found it to
be calcium-regulated and inhibited by
Immunoblotting reveals that calmodulin-like domain protein kinase(s) (CDPK)
are enriched in the purified preparation and addition of anti-CDPK to in
vitro phosphorylation assays results in the inhibition of ADF
phosphorylation. These data strongly suggest that plant ADF is
phosphorylated by CDPK(s), a class of protein kinases unique to plants