The multifunctional Ca(2+)/calmodulin-dependent protein kinase II delta (CaMKIIδ) phosphorylates cardiac titin's spring elements.

ABSTRACT: Titin-based passive stiffness is post-translationally regulated by several kinases that phosphorylate specific spring elements located within titin's elastic I-band region. Whether titin is phosphorylated by calcium/calmodulin dependent protein kinase II (CaMKII), an important regulator of cardiac function and disease, has not been addressed. The aim of this work was to determine whether CaMKIIδ, the predominant CaMKII isoform in the heart, phosphorylates titin, and to use phosphorylation assays and mass spectrometry to study which of titin's spring elements might be targeted by CaMKIIδ. It was found that CaMKIIδ phosphorylates titin in mouse LV skinned fibers, that the CaMKIIδ sites can be dephosphorylated by protein phosphatase 1 (PP1), and that under baseline conditions, in both intact

SUBMITTER: Hidalgo CG 

PROVIDER: S-EPMC3535572 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature