Stewart R, Zissimopoulos S, Lai FA. Oligomerization of the cardiac ryanodine receptor C-terminal tail.
Biochem J 2003;
376:795-9. [PMID:
12959641 PMCID:
PMC1223808 DOI:
10.1042/bj20030597]
[Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2003] [Revised: 08/22/2003] [Accepted: 09/08/2003] [Indexed: 11/17/2022]
Abstract
The C-terminal 100 amino acids of the RyR (ryanodine receptor), referred to as the C-terminal tail, is a highly conserved sequence that is present in all known RyR isoforms and which has been implicated in channel function. Deleting the final 15 amino acids from the full-length skeletal muscle RyR resulted in an inactive channel, attributed to impaired assembly of a tetrameric RyR complex [Gao, Tripathy, Lu and Meissner (1997) FEBS Lett. 412, 223-226]. To account for these observations, the C-terminal tail itself may be an important molecular determinant of oligomerization. Alternatively, the large N-terminal cytoplasmic domain may fold back upon itself to interact with the C-terminal tail to provide a correctly folded tetrameric structure. We explored these possibilities for RyR2 (cardiac RyR) using the yeast two-hybrid interaction assay and in vitro translation followed by immunoprecipitation and chemical cross-linking. The data indicate that the C-terminal tail of RyR2 is capable of self-tetramerization. Moreover, a truncated C-terminal tail, lacking the final 15 amino acids, failed to self-associate. These observations suggest that the intrinsic ability of the RyR C-terminal tail to self-tetramerize may be vitally important for the oligomeric assembly of the native RyR channel.
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