title: Polarized trafficking of thyrocyte proteins in MDCK cells.
abstract: Recent studies suggest striking similarities between polarized protein sorting in thyrocytes and MDCK epithelial cells, including apical trafficking of thyroglobulin (Tg), thyroid peroxidase, and aminopeptidase N; as well as basolateral targeting of heparan sulfate proteoglycans, thrombospondin 1 (TSP1), type 1 5'-deiodinase, sodium-potassium ATPase, and the thyrotropin receptor. In this report, we have firstly expressed in stably transfected MDCK II cells a range of truncation mutants lacking up to 78% of the C-terminus of TSP1; these studies indicate that the N-terminal region containing the heparin binding domain is sufficient for basolateral targeting of TSP1. Secondly, we have stably transfected MDCK II cells with both Tg and sodium-iodide symporter (NIS) cDNAs, obtaining clones that simultaneously express both thyroid-specific proteins at the apical and basolateral cell surfaces, respectively. These studies represent promising early steps towards designing artificial thyrocytes by thyroid gene transfer into MDCK cells.
authors.affiliation: Division of Endocrinology and Departments of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Zhang
authors.forename: Claudia
authors.initials: C
authors.lastname: Riedel
authors.forename: Nancy
authors.initials: N
authors.lastname: Carrasco
authors.forename: Peter
authors.initials: P
authors.lastname: Arvan
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000378:metabolism; D001692:Biological Transport; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D002478:Cells, Cultured; D002999:Clone Cells; D004247:DNA / Q000032:analysis; D004268:DNA-Binding Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D007454:Iodides / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D027981:Symporters / Q000235:genetics* / Q000378:metabolism; D019700:Thrombospondin 1 / Q000235:genetics; D013954:Thyroglobulin / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors; D014162:Transfection; D000099209:Sodium-Iodide Symporters
chemical_list: D004247:DNA; D004268:DNA-Binding Proteins; D007454:Iodides; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D027981:Symporters; D019700:Thrombospondin 1; D013954:Thyroglobulin; D014157:Transcription Factors; D000099209:Sodium-Iodide Symporters; C101206:SUB1 protein, S cerevisiae