CHROMOSOMAL MAPPING OF TMP (EMP1), XMP (EMP2), AND YMP (EMP3), GENES ENCODING MEMBRANE-PROTEINS RELATED TO PMP22

We have recently characterized a novel mammalian gene family, encoding membrane glycoproteins with four trans-membrane domains. This gene fa mily includes the previously studied PMP22, which is involved in the C harcot-Marie-Tooth neuropathy, and three novel genes: TMP, XMP, and YM P (HGMW-approved symbols EMP1, EMP2 and EMP3, respectively). The Tmp ( tumor-associated membrane protein) gene was isolated from a c-myc indu ced mouse brain tumor and is expressed in several highly proliferative cell types. We have now isolated cDNAs of the mouse Xmp and Ymp genes and determined the chromosomal localization of mouse Tmp, Xmp, and Ym p. Tmp was mapped to mouse chromosome 6, Xmp was mapped to chromosome 16, and Ymp was mapped to chromosome 7. Tmp and Ymp map to paralogous chromosomal regions, whereas Xmp maps to a chromosomal region that is putatively paralogous to a region on chromosome 11, to which Pmp22 was previously mapped. These data suggest that this family of membrane gl ycoproteins evolved as a result of chromosomal duplications, (C) 1998 Academic Press.