Fachbereich Veterinärmedizin



    Molecular Cloning and Biochemical Characterization of a Truncated, Secreted Member of the Human Family of Ca2+-activated Cl- Channels (1999)

    Zeitschriftenartikel / wissenschaftlicher Beitrag
    Gruber, A D (WE 12)
    Pauli, B U
    Biochimica et biophysica acta; 1444(3) — S. 418–423
    ISSN: 0006-3002
    Pubmed: 10095065
    Institut für Tierpathologie

    Robert-von-Ostertag-Str. 15
    Gebäude 12
    14163 Berlin
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    Abstract / Zusammenfassung

    A novel family of chloride channel proteins has recently been discovered including two bovine (Lu-ECAM-1, bCLCA1), one murine (mCLCA1), and two human (hCLCA1 and hCLCA2) members. Here, we describe the cloning, expression, and molecular characterization of a truncated human homolog, tentatively named hCLCA3. It was cloned from a human spleen cDNA library and is expressed in numerous tissues including lung, trachea, spleen, thymus, and mammary gland as determined by reverse transcriptase-polymerase chain reaction. Unlike all previously known CLCA family members which consistently encode an approximately 125-kDa transmembrane protein that is cleaved to form a heterodimer of two proteins of approximately 90 and 35 kDa, the 3.6-kb hCLCA3 mRNA encodes a 37-kDa glycoprotein that corresponds to the N-terminal extracellular domain of its homologs. Moreover, when expressed in human embryonic kidney 293 or Chinese hamster ovary cells, this 37-kDa glycoprotein is secreted into the culture supernatant. These observations suggest that hCLCA3 is a structurally divergent member of the CLCA family of proteins and that it does not act as a channel protein but has distinct, yet unidentified functions.