Journal article
Caldesmon, N-Terminal Yeast Actin Mutants, and the Regulation of Actomyosin Interactions
Biochemistry (Easton), Vol.33(11), pp.3210-3216
03/01/1994
DOI: 10.1021/bi00177a010
PMID: 8136356
Abstract
N-Terminal yeast actin mutants were used to assess the role of N-terminal acidic residues in the interactions of caldesmon with actin. The yeast actins differed only in their N-terminal charge: wild type, two negative charges; 4Ac, four negative charges; DNEQ, neutral charge; delta DSE, one positive charge. Caldesmon inhibition of actomyosin subfragment 1 ATPase was affected by alterations in the N-terminus of actin. This inhibition was similar for skeletal muscle alpha-actin and the yeast 4Ac and wild-type actins (80%), but much smaller for the neutral and deletion mutants (15%). However, cosedimentation experiments revealed similar binding of caldesmon to polymerized rabbit skeletal muscle alpha-actin and each yeast actin. This result shows that the N-terminal acidic residues of actin are not required for the binding of caldesmon to F-actin. Caldesmon-actin interactions were also examined by monitoring the polymerization of G-actin induced by caldesmon. Although the final extent of polymerization was similar for all actins tested, the rates of polymerization differed. Skeletal muscle and 4Ac actins had similar rates of polymerization, and the wild-type actin polymerized at a slower rate. The neutral and deletion mutants had even slower rates of polymerization by caldesmon. The slow polymerization of DNEQ G-actin was traced to a greatly reduced binding of caldesmon to this mutant G-actin when compared to wild-type and alpha-actin. MgCl2-induced actin polymerization proceeded at identical rates for all actins.(ABSTRACT TRUNCATED AT 250 WORDS)
Details
- Title: Subtitle
- Caldesmon, N-Terminal Yeast Actin Mutants, and the Regulation of Actomyosin Interactions
- Creators
- Rachelle H CrosbieCarl MillerJoseph M ChalovichPeter A RubensteinEmil Reisler
- Resource Type
- Journal article
- Publication Details
- Biochemistry (Easton), Vol.33(11), pp.3210-3216
- Publisher
- American Chemical Society
- DOI
- 10.1021/bi00177a010
- PMID
- 8136356
- ISSN
- 0006-2960
- eISSN
- 1520-4995
- Language
- English
- Date published
- 03/01/1994
- Academic Unit
- Stead Family Department of Pediatrics; Biochemistry and Molecular Biology; Internal Medicine
- Record Identifier
- 9984024404702771
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