Cloning and characterization of fiber type-specific ryanodine receptor isoforms in skeletal muscles of fish.
We have cloned a group of cDNAs that encodes the skeletal ryanodine receptor isoform (RyR1) of fish from a blue marlin extraocular muscle library. The cDNAs encode a protein of 5,081 amino acids with a calculated molecular mass of 576,302 Da. The deduced amino acid sequence shows strong sequence identity to previously characterized RyR1 isoforms. An RNA probe derived from a clone of the full-length marlin RyR1 isoform hybridizes to RNA preparations from extraocular muscle and slow-twitch skeletal muscle but not to RNA preparations from fast-twitch skeletal or cardiac muscle. We have also isolated a partial RyR clone from marlin and toadfish fast-twitch muscles that shares 80% sequence identity with the corresponding region of the full-length RyR1 isoform, and a RNA probe derived from this clone hybridizes to RNA preparations from fast-twitch muscle but not to slow-twitch muscle preparations. Western blot analysis of slow-twitch muscles in fish indicates the presence of only a single high-molecular-mass RyR protein corresponding to RyR1. [3H]ryanodine binding assays revealed the fish slow-twitch muscle RyR1 had a greater sensitivity for Ca2+ than the fast-twitch muscle RyR1. The results indicate that, in fish muscle, fiber type-specific RyR1 isoforms are expressed and the two proteins are physiologically distinct.
Stanford University, Hopkins Marine Station, Pacific Grove, California 93950, USA.
J P
JP
Franck
J
J
Morrissette
J E
JE
Keen
R L
RL
Londraville
M
M
Beamsley
B A
BA
Block
D000595:Amino Acid Sequence; D000818:Animals; D016375:Antisense Elements (Genetics); D001483:Base Sequence; D001665:Binding Sites; D002118:Calcium / Q000494:pharmacology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers; D005399:Fishes; D006801:Humans; D008969:Molecular Sequence Data; D018656:Muscle Fibers, Fast-Twitch / Q000502:physiology*; D018657:Muscle Fibers, Slow-Twitch / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D015345:Oligonucleotide Probes; D010802:Phylogeny; D011817:Rabbits; D011898:Ranidae; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D015183:Restriction Mapping; D019837:Ryanodine Receptor Calcium Release Channel / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D016375:Antisense Elements (Genetics); D017931:DNA Primers; D015345:Oligonucleotide Probes; D011994:Recombinant Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002118:Calcium