title: Regulation of the expression of the prostate-specific antigen by claudin-7.
abstract: Claudins are a family of proteins involved in forming tight junctions between cells. Here we describe two forms of claudin-7 (CLDN-7), a full-length form of CLDN-7 with 211 amino-acid residues and a C-terminal truncated form with 158 amino-acid residues. These two forms of CLDN-7 are able to regulate the expression of a tissue-specific protein, the prostate-specific antigen (PSA), in the LNCaP prostate cancer cell line. We also found that the expression of CLDN-7 is responsive to androgen stimulation in the LNCaP cell line, suggesting that this protein is involved in the regulatory mechanism of androgen. Both forms of claudin-7 are expressed in human prostate, kidney and lung samples, and in most samples, the full-length form of claudin-7 was predominant. However, in some prostate samples from healthy individuals, the truncated form of claudin-7 is predominantly expressed. Our results demonstrated that unlike other claudins, CLDN-7 has both structural and regulatory functions, and the two forms of CLDN-7 may be related to cell differentiation in organ development.
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D000595:Amino Acid Sequence; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D057167:Claudins; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D009928:Organ Specificity; D017430:Prostate-Specific Antigen / Q000096:biosynthesis* / Q000235:genetics; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D020033:Protein Isoforms / Q000737:chemistry / Q000502:physiology; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000502:physiology; D013329:Structure-Activity Relationship; D013382:Subtraction Technique; D019108:Tight Junctions / Q000502:physiology; D014162:Transfection
chemical_list: C473255:CLDN7 protein, human; D057167:Claudins; D018076:DNA, Complementary; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011993:Recombinant Fusion Proteins; D017430:Prostate-Specific Antigen