Sortilin is the major 110-kDa protein in GLUT4 vesicles from adipocytes

• Published in: The Journal of biological chemistry 1998-02, Vol.273 (6), p.3582-3587
• Main Authors: Morris, N.J, Ross, S.A, Lane, W.S, Moestrup, S.K, Petersen, C.M, Keller, S.R, Lienhard, G.E
• Format: Article
• Language: English
• Subjects: 3T3 Cells; Adaptor Proteins, Vesicular Transport; Adipocytes - drug effects; Adipocytes - metabolism; ADIPOSE TISSUES; ADN; Amino Acid Sequence; AMINO ACID SEQUENCES; Animals; Base Sequence; Biological Transport; CELL DIFFERENTIATION; Cell Membrane - drug effects; Cell Membrane - metabolism; CELL MEMBRANES; CELLS; CELLULE; CELULAS; CHEMICAL COMPOSITION; COMPLEMENTARY DNA; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; CYTOPLASMIC ORGANELLES; DIFERENCIACION CELULAR; DIFFERENCIATION CELLULAIRE; DNA; DNA, Complementary; GENBANK/AF019109; GLUCOSE TRANSPORTER; Glucose Transporter Type 4; IMMUNOCYTOCHEMISTRY; IMMUNOLOGIE; IMMUNOLOGY; INMUNOLOGIA; INSULIN; INSULINA; INSULINE; MEMBRANAS CELULARES; MEMBRANE CELLULAIRE; Membrane Glycoproteins - genetics; Membrane Glycoproteins - metabolism; METABOLISME DES PROTEINES; METABOLISMO PROTEICO; MICE; MICROSOMES; MOLECULAR SEQUENCE DATA; Monosaccharide Transport Proteins - metabolism; Muscle Proteins; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; NUCLEOTIDE SEQUENCE; ORGANITE CELLULAIRE; ORGANULOS CITOPLASMICOS; PLASMA MEMBRANES; PROTEIN METABOLISM; PROTEIN TRANSPORT; PROTEINAS; PROTEINE; PROTEINS; RAT; RATA; RATON; RATS; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; SECUENCIA NUCLEOTIDICA; SEQUENCE NUCLEOTIDIQUE; SOURIS; Subcellular Fractions - metabolism; SURFACE PROTEINS; TEJIDO ADIPOSO; TISSU ADIPEUX
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.273.6.3582

Vesicles containing the glucose transporter GLUT4 from rat adipocytes contain a major protein of 110 kDa. We have isolated this protein, obtained the sequences of peptides, and cloned a large portion of its cDNA. This revealed that the protein is sortilin, a novel membrane protein that was cloned in another context from a human source while this work was in progress. Subcellular fractionation of rat and 3T3-L1 adipocytes, together with GLUT4 vesicle isolation, showed that sortilin was primarily located in the low density microsomes in vesicles containing GLUT4. Insulin caused a 1.7-fold increase in the amount of sortilin at the plasma membranes of 3T3-L1 adipocytes, as assessed by cell surface biotinylation. The expression of sortilin in 3T3-L1 cells occurred only upon differentiation. Previous characterization of sortilin has led to the suggestion that it functions to sort lumenal proteins from the trans Golgi. The significance of its insulin-stimulated increase at the cell surface and of its expression upon differentiation will require definitive delineation of its function.