Journal article
Alternate pathways for removal of the class II actin initiator methionine
The Journal of biological chemistry, Vol.262(13), pp.6350-6356
1987
DOI: 10.1016/S0021-9258(18)45577-9
PMID: 3571262
Abstract
Class II actin genes usually specify a polypeptide with a Met-Cys-Asp NH2 terminus, whereas the actin itself begins with an acetyl (Ac)-Asp(Glu). Previous studies with Drosophila actin showed that the first detectable intermediate is one with an Ac-Cys NH2 terminus which is subsequently cleaved in a novel reaction to expose the Asp. The initiator Met was probably removed early in translation as a free amino acid. To determine whether the class II actin initiating Met could also be removed in an acetylation-dependent manner, we translated Drosophila mRNA in a rabbit reticulocyte lysate in which protein acetylation was inhibited. After 60 min, three actin intermediates were detected, NH2-Met-Cys-Asp-actin, Ac-Met-Cys-Asp-actin, and NH2-Cys-Asp-actin. During processing in the presence of acetyl-CoA, three additional species were observed with NH2-terminal Ac-Cys-Asp, NH2-Asp, and Ac-Asp segments. In a time- and acetyl-CoA-dependent fashion, Met-Cys-Asp-actin was processed to the mature actin, presumably through an Ac-Met-Cys-Asp intermediate. Thus, two different pathways for removal of the initiator Met of class II actins, acetylation-dependent and independent, are possible. Since no class II actin intermediate containing the initiator Met is seen in vivo, although in class I actins this intermediate is observed, the most probable pathway for class II actins in vivo is the cotranslational removal of the initiator Met as a free amino acid.
Details
- Title: Subtitle
- Alternate pathways for removal of the class II actin initiator methionine
- Creators
- Debra J Martin - Univ. Iowa, dep. biochemistry, Iowa City IA 52242, United StatesPeter A Rubenstein - Univ. Iowa, dep. biochemistry, Iowa City IA 52242, United States
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.262(13), pp.6350-6356
- DOI
- 10.1016/S0021-9258(18)45577-9
- PMID
- 3571262
- 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
- 1987
- Academic Unit
- Stead Family Department of Pediatrics; Biochemistry and Molecular Biology; Internal Medicine
- Record Identifier
- 9984024515202771
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