3 GENES IN THE HUMAN MHC CLASS-III REGION NEAR THE JUNCTION WITH THE CLASS-II - GENE FOR RECEPTOR OF ADVANCED GLYCOSYLATION END-PRODUCTS, PBX2 HOMEOBOX GENE AND A NOTCH HOMOLOG, HUMAN COUNTERPART OF MOUSE MAMMARY-TUMOR GENE INT-3

Cosmid walking of about 250 kb from MHC class III gene CYP21 to class II was conducted. The gene for receptor of advanced glycosylation end products of proteins (RAGE, a member of immunoglobulin superfamily mol ecules), the PBX2 homeobox gene designated HOX12, and the human counte rpart of the mouse mammary tumor gene int-3 were found. The contiguous RAGE and HOX12 genes were completely sequenced, and the human int-3 c ounterpart was partially sequenced and assigned to a Notch homolog. Th is human Notch homolog, designated NOTCH3, showed both the intracellul ar portion present in the mouse int-3 sequence and the extracellular p ortion absent in the int-3. It thus corresponds to the intact form of a Notch-type transmembrane protein. About 20 kb of dense Alu clusterin g was found just centromeric to the NOTCH3. (C) 1994 Academic Press, I nc.