THE CHARACTERIZATION OF A HUMAN RHAMM CDNA - CONSERVATION OF THE HYALURONAN-BINDING DOMAINS

A full-length human RHAMM cDNA clone was isolated by a combination of screening a human breast cDNA expression library with the murine RHAMM 2 cDNA as well as 5' RACE and RT-PCR using messenger RNA from human b reast cell line (MCF-10A). The full-length cDNA contained 725 aa that encoded an 84 kDa protein. Although the coding region of the human RHA MM cDNA resembles the murine RHAMM v4, it has additional unique N-term inal (489 bp) and C-terminal (33 bp) regions. Also, only 1 of 5 repeat sequences encoded in the murine cDNA are present in human cDNA. The o verall homology between the overlapping region of human and mouse RHAM M v4 cDNA clone is 85%, but the HA binding motif (B[X(7)]B), shown to be critical for the signaling capability of this receptor, is 100% con served.