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Site-specific phosphorylation and point mutations of telokin modulate its Ca2+-desensitizing effect in smooth muscle.

Publication ,  Journal Article
Walker, LA; MacDonald, JA; Liu, X; Nakamoto, RK; Haystead, TA; Somlyo, AV; Somlyo, AP
Published in: J Biol Chem
July 6, 2001

Forskolin and 8-bromoguanosine 3'-5'-cyclic monophosphate (8-Br-cGMP) induce phosphorylation of Ser-13 of telokin and relaxation of smooth muscle at constant calcium. Comparison with the effect of wild type with aspartate (D; to mimic phosphorylation) and alanine (A; non-phosphorylatable) mutants of telokin showed that the S13D mutant was more effective than wild type in relaxing smooth muscle at constant calcium. The efficacy of the Ser-13A, S12A, and S12D mutants was not significantly different from that of wild-type telokin. The effect of neither S13D nor Ser-13A was affected by 8-Br-cGMP, whereas the effect of wild type, S12A, and S12D was enhanced by 8-Br-cGMP, indicating the specificity of Ser-13 charge modification. Mutation of Ser-19 (a mitogen-activated protein kinase site) showed the S19A to be more effective than, and S19D to be not different from, wild-type telokin. The effect of both mutants was slightly enhanced by 8-Br-cGMP. A truncated (residues 1-142) form lacking the acidic C terminus had the same relaxant effect as wild-type telokin, whereas the C-terminal peptide (residues 142-155) had no effect. We conclude that site-specific modification of the N terminus modulates the Ca2+ -desensitizing effect of telokin on force.

Duke Scholars

Published In

J Biol Chem

DOI

ISSN

0021-9258

Publication Date

July 6, 2001

Volume

276

Issue

27

Start / End Page

24519 / 24524

Location

United States

Related Subject Headings

  • Serine
  • Rabbits
  • Point Mutation
  • Phosphorylation
  • Peptides, Cyclic
  • Peptides
  • Peptide Fragments
  • Myosin-Light-Chain Kinase
  • Muscle, Smooth
  • Muscle Relaxation
 

Citation

APA
Chicago
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MLA
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Walker, L. A., MacDonald, J. A., Liu, X., Nakamoto, R. K., Haystead, T. A., Somlyo, A. V., & Somlyo, A. P. (2001). Site-specific phosphorylation and point mutations of telokin modulate its Ca2+-desensitizing effect in smooth muscle. J Biol Chem, 276(27), 24519–24524. https://doi.org/10.1074/jbc.M103560200
Walker, L. A., J. A. MacDonald, X. Liu, R. K. Nakamoto, T. A. Haystead, A. V. Somlyo, and A. P. Somlyo. “Site-specific phosphorylation and point mutations of telokin modulate its Ca2+-desensitizing effect in smooth muscle.J Biol Chem 276, no. 27 (July 6, 2001): 24519–24. https://doi.org/10.1074/jbc.M103560200.
Walker LA, MacDonald JA, Liu X, Nakamoto RK, Haystead TA, Somlyo AV, et al. Site-specific phosphorylation and point mutations of telokin modulate its Ca2+-desensitizing effect in smooth muscle. J Biol Chem. 2001 Jul 6;276(27):24519–24.
Walker, L. A., et al. “Site-specific phosphorylation and point mutations of telokin modulate its Ca2+-desensitizing effect in smooth muscle.J Biol Chem, vol. 276, no. 27, July 2001, pp. 24519–24. Pubmed, doi:10.1074/jbc.M103560200.
Walker LA, MacDonald JA, Liu X, Nakamoto RK, Haystead TA, Somlyo AV, Somlyo AP. Site-specific phosphorylation and point mutations of telokin modulate its Ca2+-desensitizing effect in smooth muscle. J Biol Chem. 2001 Jul 6;276(27):24519–24524.

Published In

J Biol Chem

DOI

ISSN

0021-9258

Publication Date

July 6, 2001

Volume

276

Issue

27

Start / End Page

24519 / 24524

Location

United States

Related Subject Headings

  • Serine
  • Rabbits
  • Point Mutation
  • Phosphorylation
  • Peptides, Cyclic
  • Peptides
  • Peptide Fragments
  • Myosin-Light-Chain Kinase
  • Muscle, Smooth
  • Muscle Relaxation