UMMS Affiliation

Program in Molecular Medicine

Publication Date

8-1-1994

Document Type

Article

Subjects

Amino Acid Sequence; Animals; CHO Cells; Cell Line; Cercopithecus aethiops; Coated Pits, Cell-Membrane; Cricetinae; Deoxyglucose; *Endocytosis; Epitopes; Glucose Transporter Type 1; Glucose Transporter Type 4; Humans; Kinetics; *Leucine; Molecular Sequence Data; Monosaccharide Transport Proteins; *Muscle Proteins; Mutagenesis, Site-Directed; Rats; Recombinant Fusion Proteins; Sequence Homology, Amino Acid; Transferrin

Disciplines

Cell Biology

Abstract

The unique COOH-terminal 30-amino acid region of the adipocyte/skeletal muscle glucose transporter (GLUT4) appears to be a major structural determinant of this protein's perinuclear localization, from where it is redistributed to the cell surface in response to insulin. To test whether an underlying mechanism of this domain's function involves glucose transporter endocytosis rates, transfected cells were generated expressing exofacial hemagglutinin epitope (HA)-tagged erythrocyte/brain glucose transporter (GLUT1) or a chimera containing the COOH-terminal 30 amino acids of GLUT4 substituted onto this GLUT1 construct. Incubation of COS-7 or CHO cells expressing the HA-tagged chimera with anti-HA antibody at 37 degrees resulted in an increased rate of antibody internalization compared to cells expressing similar levels of HA-tagged GLUT1, which displays a cell surface disposition. Colocalization of the internalized anti-HA antibody in vesicular structures with internalized transferrin and with total transporters was established by digital imaging microscopy, suggesting the total cellular pool of transporters are continuously recycling through the coated pit endocytosis pathway. Mutation of the unique double leucines 489 and 490 in the rat GLUT4 COOH-terminal domain to alanines caused the HA-tagged chimera to revert to the slow endocytosis rate and steady-state cell surface display characteristic of GLUT1. These results support the hypothesis that the double leucine motif in the GLUT4 COOH terminus operates as a rapid endocytosis and retention signal in the GLUT4 transporter, causing its localization to intracellular compartments in the absence of insulin.

Rights and Permissions

Citation: J Cell Biol. 1994 Aug;126(4):979-89.

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

The Journal of cell biology

PubMed ID

7519625

Included in

Cell Biology Commons

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.