Smooth Muscle Tissues Express a Major Dominant Negative Splice Variant of the Type 3 Ca2+ Release Channel (Ryanodine Receptor)
It is well known that the type 3 Ca 2+ release channel (ryanodine receptor, RyR3) exhibits strikingly different pharmacological and functional properties depending on the tissues in which it resides. To investigate the molecular basis for this tissue-dependent heterogeneity, we examined the primary...
Saved in:
Published in | The Journal of biological chemistry Vol. 278; no. 7; pp. 4763 - 4769 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Biochemistry and Molecular Biology
14.02.2003
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | It is well known that the type 3 Ca 2+ release channel (ryanodine receptor, RyR3) exhibits strikingly different pharmacological and functional properties depending
on the tissues in which it resides. To investigate the molecular basis for this tissue-dependent heterogeneity, we examined
the primary structure of RyR3 from various tissues by reverse transcription polymerase chain reaction and DNA sequence analysis.
As many as seven alternatively spliced variants of RyR3 were detected. Ribonuclease protection assays revealed that one of
these splice variants, RyR3 (AS-8a), which lacks a 29-amino acid fragment (His 4406 âLys 4434 ) encompassing a predicted transmembrane helix, was highly expressed in smooth muscle tissues, but not in skeletal muscle,
the heart, or the brain. Although the RyR3 (AS-8a) splice variant did not form a functional Ca 2+ release channel when expressed alone in HEK293 cells, it was able to form functional heteromeric channels with reduced caffeine
sensitivity when co-expressed with the wild type RyR3. Interestingly, this RyR3 splice variant was also able to form heteromeric
channels with and suppress the activity of the type 2 ryanodine receptor (RyR2). Tissue-specific expression of RyR3 splice
variants is therefore likely to account for some of the pharmacological and functional heterogeneities of RyR3. These observations
also reveal a novel mechanism by which a splice variant of one RyR isoform (RyR3) can suppress the activity of another RyR
isoform (RyR2) via a dominant negative effect. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0021-9258 1083-351X |
DOI: | 10.1074/jbc.M210410200 |