Journal article
A site on transducin α-subunit of interaction with the polycationic region of cGMP phosphodiesterase inhibitory subunit
The Journal of biological chemistry, Vol.268(31), pp.23611-23615
1993
DOI: 10.1016/S0021-9258(19)49506-9
PMID: 8226888
Abstract
Activation of cGMP phosphodiesterase (PDE) by the rod G-protein transducin is a key event in visual signal transduction in vertebrate photoreceptor cells. Interaction between the GTP-bound form of the alpha-subunit of transducin (alpha t*) and the PDE inhibitory gamma-subunit (P gamma) is a major component of PDE activation. The central polycationic region of P gamma, P gamma-24-45, has been implicated as one of the sites involved in alpha t*.P gamma interaction. Here we determine the site on alpha t* that interacts with P gamma-24-45 using a photo-cross-linking approach. The synthetic peptides Cys(ACM)Tyr-P gamma-24-45-Cys (where ACM indicates acetamidomethyl group) and Cys-P gamma-24-45 were labeled with 4-(N-maleimido)benzophenone at the COOH and NH2 termini, respectively, and then cross-linked to alpha t. When the photoprobe was attached to the COOH terminus of the peptide, a specific high yield cross-linked product (80%) was formed between the peptide and alpha t GTP gamma S (guanosine 5'-O-(thiotriphosphate)). A lower yield of cross-linking (35%) was seen between the peptide and alpha t GDP. The site of cross-linking between Cys(ACM)Tyr-P gamma-24-45-Cys and alpha t GTP gamma S was localized to within alpha t-306-310 using a variety of chemical and proteolytic cleavages of the cross-linked product, analysis of the fragments with SDS-polyacrylamide gel electrophoresis, and matrix-assisted laser desorption ionization mass spectrometry.
Details
- Title: Subtitle
- A site on transducin α-subunit of interaction with the polycationic region of cGMP phosphodiesterase inhibitory subunit
- Creators
- Nikolai O Artemyev - Univ. Illinois coll. medicine, dep. physiology biophysics, Chicago IL 60680, United StatesJohn S Mills - Univ. Illinois coll. medicine, dep. physiology biophysics, Chicago IL 60680, United StatesKelly R Thornburg - Univ. Illinois coll. medicine, dep. physiology biophysics, Chicago IL 60680, United StatesDaniel R Knapp - Univ. Illinois coll. medicine, dep. physiology biophysics, Chicago IL 60680, United StatesKevin L Schey - Univ. Illinois coll. medicine, dep. physiology biophysics, Chicago IL 60680, United StatesHeidi E Hamm - Univ. Illinois coll. medicine, dep. physiology biophysics, Chicago IL 60680, United States
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.268(31), pp.23611-23615
- DOI
- 10.1016/S0021-9258(19)49506-9
- PMID
- 8226888
- 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
- 1993
- Academic Unit
- Molecular Physiology and Biophysics; Iowa Neuroscience Institute; Ophthalmology and Visual Sciences
- Record Identifier
- 9984025566102771
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