Journal article
Identification of N-acetylmethionine as the product released during the NH2-terminal processing of a pseudo-class I actin
The Journal of biological chemistry, Vol.264(19), pp.11491-11496
1989
DOI: 10.1016/S0021-9258(18)60490-9
PMID: 2738074
Abstract
Genes for the various isoactins define two classes of actin. Class I actin genes code for Met-Asp(Glu)-actin, and class II actin genes code for Met-X-Asp(Glu)-actin where X is usually cysteine. Amino termini of both are removed in an acetylation-dependent processing reaction yielding acetyl-Asp(Glu)-actin. Both classes are processed at approximately equal rate (t1/2 = 15 min) in vivo. In vitro, class II actins are 90% processed by endogenous enzymes after 60 min in a rabbit reticulocyte lysate system, whereas class I actins are only minimally processed during this period. Using site-directed mutagenesis of a human skeletal muscle isoactin coupled with in vitro transcription and translation methods, we have synthesized a pseudo-class I actin in which the penultimate cysteine has been changed to an aspartic acid, thus placing a class I amino terminus on an otherwise class II actin molecule. The pseudo-class I actin was less than 20% processed during the translation period as determined by peptide mapping. It was further processed by exogenous processing enzyme at a rate compatible with a class I actin. These results indicate that the major actin determinant controlling differential actin-processing rates is the amino-terminal residue being cleaved, not the remaining structure of the actin molecule. We have also demonstrated for the first time that N-acetylmethionine is the immediately released product from the amino terminus of a pseudo-class I actin during processing.
Details
- Title: Subtitle
- Identification of N-acetylmethionine as the product released during the NH2-terminal processing of a pseudo-class I actin
- Creators
- David R Sheff - Univ. Iowa coll. medicine, dep. biochemistry, Iowa City IA 52242, United StatesPeter A Rubenstein - Univ. Iowa coll. medicine, dep. biochemistry, Iowa City IA 52242, United States
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.264(19), pp.11491-11496
- DOI
- 10.1016/S0021-9258(18)60490-9
- PMID
- 2738074
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Publisher
- American Society for Biochemistry and Molecular Biology; Bethesda, MD
- Language
- English
- Date published
- 1989
- Academic Unit
- Stead Family Department of Pediatrics; Family and Community Medicine; Biochemistry and Molecular Biology; Internal Medicine
- Record Identifier
- 9984025249502771
Metrics
16 Record Views