AMINO-ACID-SEQUENCE OF A CA2-TRANSPORTING ATPASE FROM THE SARCOPLASMIC-RETICULUM OF THE CROSS-STRIATED PART OF THE ADDUCTOR MUSCLE OF THE DEEP-SEA SCALLOP - COMPARISON TO SERCA ENZYMES OF OTHER ANIMALS()

The RT PCR approach was used to obtain the nucleotide sequence of the mRNA of a sarco/endoplasmic reticulum calcium transporting ATPase (SER CA) from the cross-striated (phasic) part of the adductor muscle of th e deep sea scallop. Initially, degenerate primers based on consensus s equences among SERCAs and tryptic fragments of the scallop Ca-ATPase w ere used. The sequence was then extended using homologous primers and the 5' and 3' ends of the transcript determined by 5' and 3' RACE. The mRNA codes for a polypeptide chain 994 amino acid residues long (code d for by 2982 nucleotides) and has a 195 bp 5' untranslated region, wi th a 697 bp 3' untranslated region. The scallop enzyme shows strongest amino acid similarity to the SERCA enzyme of Loligo, followed by thos e of Drosophila and Artemia. It resembles the vertebrate SERCA3 in tha t it does not possess the phospholamban binding motif and so is unlike ly to be regulated by protein kinase PI mediated signals. (C) 1998 Els evier Science Inc. All rights reserved.