Send to

Choose Destination
See comment in PubMed Commons below
J Proteome Res. 2011 Oct 7;10(10):4547-55. doi: 10.1021/pr200355w. Epub 2011 Sep 22.

Myosin binding protein-C slow is a novel substrate for protein kinase A (PKA) and C (PKC) in skeletal muscle.

Author information

University of Maryland , School of Medicine, Department of Biochemistry and Molecular Biology, 108 North Greene Street, Baltimore, Maryland 21201, United States.


Myosin Binding Protein-C slow (MyBP-C slow), a family of thick filament-associated proteins, consists of four alternatively spliced forms, namely variants 1-4. Variants 1-4 share common structures and sequences; however, they differ in three regions: variants 1 and 2 contain a novel 25-residue long insertion at the extreme NH(2)-terminus, variant 3 carries an 18-amino acid long segment within immunoglobulin (Ig) domain C7, and variant 1 contains a unique COOH-terminus consisting of 26-amino acids, while variant 4 does not possess any of these insertions. Variants 1-4 are expressed in variable amounts among skeletal muscles, exhibiting different topographies and potentially distinct functions. To date, the regulatory mechanisms that modulate the activities of MyBP-C slow are unknown. Using an array of proteomic approaches, we show that MyBP-C slow comprises a family of phosphoproteins. Ser-59 and Ser-62 are substrates for PKA, while Ser-83 and Thr-84 are substrates for PKC. Moreover, Ser-204 is a substrate for both PKA and PKC. Importantly, the levels of phosphorylated skeletal MyBP-C proteins (i.e., slow and fast) are notably increased in mouse dystrophic muscles, even though their overall amounts are significantly decreased. In brief, our studies are the first to show that the MyBP-C slow subfamily undergoes phosphorylation, which may regulate its activities in normalcy and disease.

[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society Icon for PubMed Central
    Loading ...
    Support Center