title: MDC-L, a novel metalloprotease disintegrin cysteine-rich protein family member expressed by human lymphocytes.
abstract: The metalloprotease disintegrin cysteine-rich (MDC) proteins are a recently identified family of transmembrane proteins that function in proteolytic processing of cell surface molecules and in cell adhesion. Since lymphocytes must interact with a constantly changing environment, we hypothesized that lymphocytes would express unique MDC proteins. To identify MDC proteins expressed in human lymph node, a polymerase chain reaction-based strategy combined with degenerate oligonucleotide primers was employed. We report here the identification of MDC-L (ADAM 23), a novel member of the MDC protein family. The results obtained from cDNA cloning and Northern blot analysis of mRNA isolated from various lymphoid tissues indicate that a 2.8-kilobase mRNA encoding a transmembrane form, MDC-Lm, and a 2.2-kilobase mRNA encoding a secreted form, MDC-Ls, are expressed in a tissue-specific manner. MDC-L mRNA was shown to be predominantly expressed in secondary lymphoid tissues, such as lymph node, spleen, small intestine, stomach, colon, appendix, and trachea. Furthermore, immunohistochemical staining with an anti-MDC-L antibody demonstrated that cells with typical lymphocyte morphology are responsible for expression of the MDC-L antigen in these lymphoid tissues. MDC-Lm was found to be expressed on the surface of human peripheral blood lymphocytes and transformed B- and T-lymphocyte cell lines as an 87-kDa protein. Thus, we have identified a novel lymphocyte-expressed MDC protein family member.
authors.affiliation: Department of Biochemistry, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73190, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Roberts
authors.forename: P H
authors.initials: PH
authors.lastname: Tani
authors.forename: L C
authors.initials: LC
authors.lastname: Bridges
authors.forename: Z
authors.initials: Z
authors.lastname: Laszik
authors.forename: R D
authors.initials: RD
authors.lastname: Bowditch
mesh_terms: D051722:ADAM Proteins; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D019483:Disintegrins; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes; D008214:Lymphocytes; D008666:Metalloendopeptidases / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D019483:Disintegrins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D051722:ADAM Proteins; C121259:Adam23 protein, mouse; D008666:Metalloendopeptidases