Polarized trafficking of thyrocyte proteins in MDCK cells.
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.
Zhang
Xiaoqing
X
Division of Endocrinology and Departments of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
Riedel
Claudia
C
Carrasco
Nancy
N
Arvan
Peter
P
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
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