Assignment1 of TACSTD1 (alias TROP1, M4S1) to human chromosome 2p21 and refinement of mapping of TACSTD2 (alias TROP2, M1S1) to human chromosome 1p32 by in situ hybridization

Abstract

TACSTD1 (alias TROP1, M4S1; OMIM 600718) and TACSTD2 (alias TROP2, M1S1; OMIM 137290) encode cellsurface glycoproteins expressed in epithelial cells. Trops are calcium signal transducers (Ripani et al., 1998), are overexpressed by human carcinomas and play a role in the control of tumor cell growth (manuscript in preparation). TACSTD2 (originally called M1S1; Fornaro et al., 1995) is responsible for the gelatinous drop-like corneal dystrophy (OMIM 204870) (Tsujikava et al., 1999). Although placed within a YAC/BAC/ cosmid contig on 1p (Tsujikava et al., 1999), its chromosome location still is undecided at 1p32→p31 or 1p13→q12 (Linnenbach et al., 1993; UniGene Hs.23582). By fluorescence in situ hybridization (FISH) we assign TACSTD2 to 1p32. The growth-suppressing properties of TACSTD2 and the frequent deletion of 1p32 in human tumors (White et al., 1999) suggest that this gene is a candidate to be a novel oncosuppressor. TACSTD1 (formerly called M4S1) shares a 49%-similar cDNA sequence with TACSTD2. TACSTD1 was localized to 4q by human/rodent somatic cell hybrid analyses (Linnenbach et al., 1993) (UniGene Hs.692). We reassign TACSTD1 to human chromosome 2p21, a region which contains the MSH2 and MSH6 DNA mismatch repair genes (Papadopoulos et al., 1995). In agreement with the HUGO Gene Nomenclature Committee, the M4S1 and M1S1 genes have been renamed TACSTD (tumor-associated calcium signal transducer) 1 and 2, respectively.