Identification of a new family of human epithelial protein kinases containing two leucine/isoleucine-zipper domains.

Using the polymerase chain reaction to study mRNA expressed in human epithelial tumor cells, a member of a new family of protein kinases was identified. The catalytic domain of this kinase has amino-acid-sequence similarity to both the Tyr-specific and the Ser/Thr-specific kinase classes. Clones representing two members of this new family have been isolated from a human colonic epithelial cDNA library and sequenced.

Expression of the tumor-associated mucin MUC1 in an ovarian tumor cell line.

Epithelial sialomucins constitute a family of high-molecular-weight glycoproteins associated with epithelial cell surfaces. Aberrant expression of these molecules has been observed in certain types of human epithelial tumors. Members of the MUC1 family of mucins isolated from different tissue types have been shown to differ in biochemical properties and in immunological reactivity.

Immunohistochemical markers of human sebaceous gland differentiation.

Cryostat sections of human skin were stained with monoclonal antibodies to involucrin, a range of cytokeratins, epithelial membrane antigen (EMA), and an ovarian cystadenocarcinoma antibody (OM1) to identify combinations of antibodies that could be used to discriminate between basal and differentiated sebocytes and other cell types present in the pilosebaceous unit. Both the EMA and OM1 monoclonal antibodies specifically recognized differentiated sebocytes. No staining of basal sebocytes or other epidermal cell types was seen.

The ovarian-carcinoma-associated sebaceous gland antigen is a member of the HMFG2-positive family of epithelial mucins.

The ovarian-carcinoma-associated sebaceous gland antigen (SGA) defined by the OM-1 monoclonal antibody (McAb) is a highly glycosylated protein of molecular weight approximately 360 kilodaltons. The HMFG1 and HMFG2 McAbs also detect highly glycosylated high-molecular-weight glycoproteins synthesized by a wide variety of human epithelia. Comparison of the distributions of expression of SGA and the molecules detected by the HMFG1 and HMFG2 McAbs showed that SGA was expressed by a strict subset of HMFG1- and HMFG2-positive cells.

Monoclonal antibodies to sheep MHC class II molecules recognize all HLA-D or subsets of HLA-D region products.

Six murine monoclonal antibodies raised against sheep MHC class II molecules were analyzed for reactivity with HLA-D subregion products. All the antibodies reacted with human peripheral blood lymphocytes, monocytes, and B-lymphoblastoid cell lines homozygous for various HLA-DR specificities, suggesting that the antibodies recognized nonpolymorphic determinants on HLA class II molecules. SDS-PAGE and two-dimensional NEPHGE/SDS-PAGE analyses of molecules immunoprecipitated from 35S-methionine-labeled, DR-homozygous B-lymphoblastoid cell lines showed that the monoclonal antibodies precipitated typical class II molecules (Mr 32-34K and 25-29K).