PMID- 10594043
OWN - NLM
STAT- MEDLINE
DCOM- 20000110
LR  - 20190508
IS  - 0270-7306 (Print)
IS  - 0270-7306 (Linking)
VI  - 20
IP  - 1
DP  - 2000 Jan
TI  - Characterization of insulin-responsive GLUT4 storage vesicles isolated from
      3T3-L1 adipocytes.
PG  - 416-27
AB  - Insulin regulates glucose transport in muscle and adipose tissue by triggering
      the translocation of a facilitative glucose transporter, GLUT4, from an
      intracellular compartment to the cell surface. It has previously been suggested
      that GLUT4 is segregated between endosomes, the trans-Golgi network (TGN), and a 
      postendosomal storage compartment. The aim of the present study was to isolate
      the GLUT4 storage compartment in order to determine the relationship of this
      compartment to other organelles, its components, and its presence in different
      cell types. A crude intracellular membrane fraction was prepared from 3T3-L1
      adipocytes and subjected to iodixanol equilibrium sedimentation analysis. Two
      distinct GLUT4-containing vesicle peaks were resolved by this procedure. The
      lighter of the two peaks (peak 2) was comprised of two overlapping peaks: peak 2b
      contained recycling endosomal markers such as the transferrin receptor (TfR),
      cellubrevin, and Rab4, and peak 2a was enriched in TGN markers (syntaxin 6, the
      cation-dependent mannose 6-phosphate receptor, sortilin, and sialyltransferase). 
      Peak 1 contained a significant proportion of GLUT4 with a smaller but significant
      amount of cellubrevin and relatively little TfR. In agreement with these data,
      internalized transferrin (Tf) accumulated in peak 2 but not peak 1. There was a
      quantitatively greater loss of GLUT4 from peak 1 than from peak 2 in response to 
      insulin stimulation. These data, combined with the observation that GLUT4 became 
      more sensitive to ablation with Tf-horseradish peroxidase following insulin
      treatment, suggest that the vesicles enriched in peak 1 are highly insulin
      responsive. Iodixanol gradient analysis of membranes isolated from other cell
      types indicated that a substantial proportion of GLUT4 was targeted to peak 1 in 
      skeletal muscle, whereas in CHO cells most of the GLUT4 was targeted to peak 2.
      These results indicate that in insulin-sensitive cells GLUT4 is targeted to a
      subpopulation of vesicles that appear, based on their protein composition, to be 
      a derivative of the endosome. We suggest that the biogenesis of this compartment 
      may mediate withdrawal of GLUT4 from the recycling system and provide the basis
      for the marked insulin responsiveness of GLUT4 that is unique to muscle and
      adipocytes.
FAU - Hashiramoto, M
AU  - Hashiramoto M
AD  - Centre for Molecular and Cellular Biology, University of Queensland, Brisbane,
      Queensland 4072, Australia.
FAU - James, D E
AU  - James DE
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Mol Cell Biol
JT  - Molecular and cellular biology
JID - 8109087
RN  - 0 (Glucose Transporter Type 4)
RN  - 0 (Hypoglycemic Agents)
RN  - 0 (Insulin)
RN  - 0 (Monosaccharide Transport Proteins)
RN  - 0 (Muscle Proteins)
RN  - 0 (Slc2a4 protein, mouse)
SB  - IM
MH  - 3T3 Cells
MH  - Adipocytes/*metabolism/ultrastructure
MH  - Animals
MH  - Biological Transport/drug effects
MH  - Cytoplasmic Granules/*metabolism
MH  - Glucose Transporter Type 4
MH  - Hypoglycemic Agents/*pharmacology
MH  - Insulin/*pharmacology
MH  - Mice
MH  - Monosaccharide Transport Proteins/*metabolism
MH  - *Muscle Proteins
PMC - PMC85096
EDAT- 1999/12/14 00:00
MHDA- 1999/12/14 00:01
CRDT- 1999/12/14 00:00
PHST- 1999/12/14 00:00 [pubmed]
PHST- 1999/12/14 00:01 [medline]
PHST- 1999/12/14 00:00 [entrez]
AID - 10.1128/mcb.20.1.416-427.2000 [doi]
PST - ppublish
SO  - Mol Cell Biol. 2000 Jan;20(1):416-27. doi: 10.1128/mcb.20.1.416-427.2000.