THE CLONING AND EXPRESSION OF A HUMAN CREATINE TRANSPORTER

A human creatine transporter (hCRT-BS2M) cDNA clone was isolated from a human brainstem/spinal cord using a PCR and phage plaque hybridizati on based technique. This clone included an open reading frame of 1,905 base pairs(bp) within a 2,283bp cDNA. Northern blot hybridization det ected the expression of corresponding mRNAs most prominently in the sk eletal muscle, heart and kidney. Peptide sequence analysis of the hCRT -BS2M protein product revealed 12 putative transmembrane domains. The predicted protein sequence further demonstrates that the hCRT-BS2M has highly conserved amino acid identity with the other members of the so dium dependent plasma membrane transporter family. Transient expressio n of the hCRT-BS2M in COS-7 cells demonstrates sodium dependent [C-14] creatine uptake with a K-M value of 14.9 +/- 3.0 mu M (n=5) that is at tenuated by creatine and selective structural analogues of creatine. ( C) 1994 Academic Press, Inc.