Abstract: A method for the identification of related polypeptides, using an function-based selection criterion, is disclosed. A novel human phosphatase, and nucleotide sequences coding therefor, identified by the aforementioned method and designated VHR, is also disclosed.

Abstract: A DNA fragment distinct from the epidermal growth factor receptor (EGFR) and erbB-2 genes was detected by reduced stringency hybridization of v-erbB to normal genomic human DNA. Characterization of the cloned DNA fragment mapped the region of v-erbB homology to three exons with closest homology of 64% and 67% to a contiguous region within the tyrosine kinase domains of the EGFR and erbB-2 proteins, respectively. cDNA cloning revealed a predicted 148 kd transmembrane polypeptide with structural features identifying it as a member of the erbB family, prompting designation of the new gene as erbB-3. It was mapped to human chromosome 12 ql 11-13 and was shown to be expressed as a 6.2 kb transcript in a variety of normal tissues of epithelial origin. Markedly elevated erbB-3 mRNA levels were demonstrated in certain human mammary tumor cell lines. These findings indicate that increased erbB-3 expression, as in the case of EGFR and erbB-2, plays a role in some human malignancies.

Abstract: Potent neutralizing monoclonal antibodies to the human .alpha. PDGF receptor (.alpha. PDGFR) and fragments thereof are described. These monoclonal antibodies specifically bind to an epitope on .alpha. PDGFR, inhibits PDGF binding with PDGF, antagonizes PDGF, and does not bind .beta. PDGFR receptor. A hybridoma cell line producing such a monoclonal antibody, methods of in vivo imaging of a pathological conditions and methods of inhibiting the growth of a neoplasia expressing .alpha. PDGFR, which use these monoclonal antibodies are also described. In vitro assays for detecting the presence of .alpha. PDGFR and for evaluating the binding affinity of a test compound are also described.

Abstract: A DNA fragment distinct from the epidermal growth factor receptor (EGF-R) and erbB-2 genes was detected by reduced stringency hybridization of v-erbB to normal genomic human DNA. Characterization of the cloned DNA fragment mapped the region of v-erbB homology to three exons with closest homology of 64% and 67% to a contiguous region within the tyrosine kinase domains of the EGF-R and erbB-2 proteins, respectively. cDNA cloning revealed a predicted 148 kd transmembrane polypeptide with structural features identifying it as a member of the erbB family, prompting designation of the new gene as erbB-3. It was mapped to human chromosome 12q11-13 and was shown to be expressed as a 6.2 kb transcript in a variety of normal tissues of epithelial origin. Markedly elevated erbB-3 mRNA levels were demonstrated in certain human mammary tumor cell lines. These findings indicate that increased erbB-3 expression, as in the case of EGF-R and erbB-2, plays a role in some human malignancies.

Abstract: Specific deletion mutants of ras p21 gene and specific monoclonal antibodies which recognize specific regions of the ras p21 protein have been prepared. A kit for detecting the presence of specific ras p21 proteins and their levels in a body sample has been described.