ISOLATION AND PARTIAL CLONING OF RYANODINE-SENSITIVE CA2-MUSCLE( RELEASE CHANNEL PROTEIN ISOFORMS FROM HUMAN MYOMETRIAL SMOOTH)

Partial cDNAs of the ryanodine receptor mere cloned using PCR analysis from reverse transcribed total and mRNA, extracted from freshly isola ted pregnant, non-pregnant, and cultured human myometrial smooth muscl e, The identity of these clones mas confirmed by nucleotide sequencing of the fragments and indicate the expression of both the skeletal and brain ryanodine receptor isoforms in these preparations. In freshly i solated non-pregnant myometrial tissue, membrane fractions displaying specific [H-3]ryanodine binding activities were isolated using density gradient centrifugation, SDS-PAGE of the sucrose gradient fractions i ndicated the specific comigration of a polypeptide with a molecular ma ss of similar to 544 kDa with the ryanodine binding activity.