A BRAIN-SPECIFIC TRANSCRIPT FROM THE 3'-TERMINAL REGION OF THE SKELETAL-MUSCLE RYANODINE RECEPTOR GENE

We have shown previously that the skeletal muscle ryanodine receptor m RNA of approximately 16,000 nucleotides codes 5,037 amino acid residue s constituting the calcium release channel in skeletal muscle. In this study, RNA blot hybridization analysis shows that the brain contains an RNA species with an estimated size of approximately 2,400 nucleotid es hybridizable with the 3'-terminal region of the skeletal muscle rya nodine receptor cDNA. cDNA cloning and genome analysis indicated that two transcripts differing in their start sites are produced from the s keletal muscle ryanodine receptor gene in a tissue-specific fashion, a nd that the mRNA in brain may code the carboxyl-terminal region of the ryanodine receptor molecule. cDNA expression experiments suggested th at the ATG triplet encoding Met4382 of the skeletal muscle ryanodine r eceptor can function as a translation initiation codon, and that the e xpressed protein composed of the carboxy terminal 656 amino acid resid ues of the receptor is located on the endoplasmic reticulum membrane.