IMMUNOLOGICAL AND STRUCTURAL CONSERVATION OF MAMMALIAN SKELETAL-MUSCLE GLYCOSYLPHOSPHATIDYLINOSITOL-LINKED ADP-RIBOSYLTRANSFERASES

NAD:arginine ADP-ribosyltransferases catalyze the ADP-ribosylation of arginine residues in proteins. Coding region nucleic acid and deduced amino acid sequences of a human skeletal muscle ADP-ribosyltransferase cDNA were, respectively, 80.8% and 81.3% identical to those of the ra bbit skeletal muscle transferase. A human transferase-specific cDNA pr obe detected major mRNA of 1.2 kb (mouse and rat), 3.0 kb (rabbit), 3. 8 kb (monkey), and 5.7 kb (human) upon Northern analysis. Polyclonal a nti-rabbit ADP-ribosyltransferase antibodies reacted with 36 000 M(r) proteins in partially purified transferase preparations from bovine, d og, and rabbit heart muscle and a 40 000 M(r) protein from human skele tal muscle. The human muscle ADP-ribosyltransferase cDNA, like the pre viously cloned rabbit muscle transferase, predicts predominantly hydro phobic amino- and carboxy-terminal amino acid sequences, which is char acteristic of glycosylphosphatidylinositol (GPI)-anchored proteins. On immunoblots of partially purified rabbit and human skeletal muscle AD P-ribosyltransferases, anti-cross-reacting determinant antibodies dete cted at 36 000 and 40 000 M(r), respectively, phosphatidylinositol-spe cific, phospholipase C-sensitive, GPI-anchored proteins. These data ar e consistent with the conclusion that GPI-anchored skeletal and cardia c muscle ADP-ribosyltransferases are conserved across mammalian specie s.