COMPLEMENTARY-DNA SEQUENCE FOR A 42 KDA RAT-KIDNEY CHOLINE ETHANOLAMINE KINASE/

By means of peptide sequence information, several cDNA clones encoding a 42 kDa choline/ethanolamine kinase were isolated from a rat kidney cDNA library. Eight clones were sequenced with all of them resulting i n identical overlapping nucleotide sequences. Four of them possessed e ntire open reading frame which could encode 394 amino acids with a cal culated molecular size of 45100, The predicted amino acid sequence con tained all of the internal peptide fragment sequences derived from the purified 42 kDa enzyme. When the open reading frame was introduced in to pGEX-2T vector and transfected into E. coli cells, a significant ch oline/ethanolamine kinase activity did appear in the cell lysate. A ho mology comparison with the previously reported choline kinase cDNAs (C KR1 and CKR2) from rat liver showed 66%-68% in entire nucleotide seque nces and 57%-59% in amino acid sequences, indicating that the cloned c DNA here must be a novel CK/EK gene product. (C) 1998 Elsevier Science B.V.