PXD015391

PXD015391 is an original dataset announced via ProteomeXchange.

Title	Human MyBP-C PKA-treated C0-C2 LC-MSMS
Description	Cardiac myosin-binding protein C (cMyBP-C) is a thick filament–associated protein that influences actin–myosin interactions. cMyBP-C alters myofilament structure and contractile properties in a protein kinase A (PKA) phosphorylation–dependent manner. To determine the effects of cMyBP-C and its phosphorylation on the microsecond rotational dynamics of actin filaments, we attached a phosphorescent probe to F-actin at Cys-374 and performed transient phosphorescence anisotropy (TPA) experiments. Binding of cMyBP-C N-terminal domains (C0-C2) to labeled F-actin reduced rotational flexibility by 20–25º, indicated by increased final anisotropy of the TPA decay. The effects of C0-C2 on actin TPA were highly cooperative (n ~ 8), suggesting that the cMyBP-C N terminus impacts the rotational dynamics of actin spanning seven monomers (i.e. the length of tropomyosin). PKA-mediated phosphorylation of C0-C2 eliminated the cooperative effects on actin flexibility and modestly increased actin rotational rates. Effects of Ser-to-Asp phosphomimetic substitutions in the M-domain of C0-C2 on actin dynamics only partially recapitulated the phosphorylation effects. C0-C1 (lacking M-domain/C2) similarly exhibited reduced cooperativity, but not as reduced as by phosphorylated C0-C2. These results suggest an important regulatory role of the M-domain in cMyBP-C effects on actin structural dynamics. In contrast, phosphomimetic substitution of the glycogen synthase kinase (GSK3beta) site in the Pro/Ala-rich linker of C0-C2 did not significantly affect the TPA results. We conclude that cMyBP-C binding and PKA-mediated phosphorylation can modulate actin dynamics. We propose that these N-terminal cMyBP-C–induced changes in actin dynamics help explain the functional effects of cMyBP-C phosphorylation on actin–myosin interactions.
HostingRepository	PRIDE
AnnounceDate	2019-09-26
AnnouncementXML	Submission_2019-09-25_22:23:42.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Brett Colson
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: 9606;
ModificationList	phosphorylated residue
Instrument	LTQ Orbitrap

Revision	Datetime	Status	ChangeLog Entry
0	2019-09-10 02:14:10	ID requested
⏵ 1	2019-09-25 22:37:02	announced

Bunch TA, Kanassatega RS, Lepak VC, Colson BA, Human cardiac myosin-binding protein C restricts actin structural dynamics in a cooperative and phosphorylation-sensitive manner. J Biol Chem, 294(44):16228-16240(2019) [pubmed]

submitter keyword: Human, LC-MSMS, myosin binding protein C, cMyBP-C, C0-C2, C0C2, PKA, phosphorylated

Brett Allan Colson
contact affiliation	Colson lab, Dept. of Cellular & Molecular Medicine, University of Arizona, Tucson, AZ, USA
contact email	bcolson@email.arizona.edu
lab head
Brett Colson
contact affiliation	University of Arizona
contact email	bcolson@email.arizona.edu
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD015391
     1. Label: PRIDE project
     2. Name: Human MyBP-C PKA-treated C0-C2 LC-MSMS