Journal article
Amino-terminal processing of actins mutagenized at the Cys-1 residue
The Journal of biological chemistry, Vol.267(4), pp.2671-2678
1992
DOI: 10.1016/S0021-9258(18)45933-9
PMID: 1733964
Abstract
Most actins examined to date undergo a unique posttranslational modification termed processing, catalyzed by the actin N-acetylaminopeptidase. Processing is the removal of acetylmethionine from the amino terminus in class I actins with Met-Asp(Glu) amino termini. For class II actins with Met-X-Asp(Glu) amino termini, processing is the removal of the second residue as an N-acetylamino acid. Other cytosolic proteins with these amino termini are not processed suggesting that the reaction may be specific for actins. In actin, X is usually cysteine. However, there are some class II actins in which this residue is other than cysteine, suggesting a broader substrate specificity for actin N-acetylaminopeptidase than acetylmethionine or acetylcysteine. We constructed mutant actins in which this cysteine was replaced with serine, asparagine, glycine, aspartic acid, histidine, phenylalanine, and tyrosine and used these to determine the substrate specificity of rat liver actin N-acetylaminopeptidase in vitro. Amino-terminal acetylmethinonine was cleaved from adjacent aspartic acid, asparagine, or histidine, but not serine, glycine, phenylalanine, or tyrosine. Of the acetylated actin amino termini tested, only acetylmethionine and acetylcysteine were cleaved. Histidine was never N-acetylated and was not cleaved. When phenylalanine and tyrosine were adjacent to the initiator methionine, no initiator methionine was cleaved even though it was acetylated. These results suggest a narrow substrate specificity for the rat liver actin N-acetylaminopeptidase. They also demonstrate that the adjacent residue can effect actin N-acetylaminopeptidase specificity.
Details
- Title: Subtitle
- Amino-terminal processing of actins mutagenized at the Cys-1 residue
- 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.267(4), pp.2671-2678
- DOI
- 10.1016/S0021-9258(18)45933-9
- PMID
- 1733964
- 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
- 1992
- Academic Unit
- Stead Family Department of Pediatrics; Family and Community Medicine; Biochemistry and Molecular Biology; Internal Medicine
- Record Identifier
- 9984024515902771
Metrics
18 Record Views