Calcium/calmodulin-dependent protein kinase II controls integrin alpha5beta1-mediated cell adhesion through the integrin cytoplasmic domain associated protein-1alpha.

This paper provided evidence that the regulation of CHO cell adhesion on fibronectin by calcium/calmodulin-dependent protein kinase II (CaMKII) is mediated through the recently described integrin cytoplasmic domain associated protein-1alpha (ICAP-1alpha). The point mutation T38D localized within the optimal CaMKII recognition motif of ICAP-1alpha results in a strong defect in cell spreading which cannot be overcome by the inhibition of the endogenous CaMKII. This fact strongly suggests that the phosphorylation of Threonine 38 by CaMKII modulates the alpha5beta1 integrin function. Conversely, the mutation T38A produces an analog of ICAP-1alpha that cannot be phosphorylated and that stimulates cell spreading on fibronectin to a similar extent when CaMKII is inhibited. Copyright 1998 Academic Press.