Immunolocalization of glucose transporter GLUT1 in the rat placental barrier: possible role of GLUT1 and the gap junction in the transport of glucose across the placental barrier

1994 ◽  
Vol 276 (3) ◽  
pp. 411-418 ◽  
Author(s):  
Kuniaki Takata ◽  
Toshiko Kasahara ◽  
Michihiro Kasahara ◽  
Osamu Ezaki ◽  
Hiroshi Hirano
Keyword(s):  
Gap Junction ◽  
Glucose Transporter ◽  
Placental Barrier ◽  
Glucose Transporter Glut1 ◽  
Transporter Glut1

scholarly journals The role of cysteine residues in glucose-transporter-GLUT1-mediated transport and transport inhibition.

1994 ◽  
Vol 299 (3) ◽  
pp. 813-817 ◽  
Author(s):  
M Wellner ◽  
I Monden ◽  
K Keller
Keyword(s):  
Plasma Membrane ◽  
Glucose Transporter ◽  
Thiol Group ◽  
Membrane Topology ◽  
Cysteine Residues ◽  
Transport Inhibition ◽  
Transport Measurements ◽  
Glucose Transporter Glut1 ◽  
Transporter Glut1

The role of cysteine residues in transport function of the glucose transporter GLUT1 was investigated by a mutagenesis-expression strategy. Each of the six cysteine residues was individually replaced by site-directed mutagenesis. Expression of the heterologous wild-type or mutant glucose transporters and transport measurements at two hexose concentrations (50 microM and 5 mM) were undertaken in Xenopus oocytes. The catalytic activity of GLUT1 was retained, despite substitution of each single cysteine residue, which indicated that no individual residue is essential for hexose transport. This finding questions the involvement of oligomerization or intramolecular stabilization by a single disulphide bond as a prerequisite for transporter activation under basal conditions. Application of the impermeant mercurial thiol-group-reactive reagent p-chloromercuribenzenesulphonate (pCMBS) to the external or internal surface of plasma membrane demonstrated that cysteine-429, within the sixth external loop, and cysteine-207, at the beginning of the large intracellular loop which connects transmembrane segments 6 and 7, are the residues which are involved in transport inhibition by impermeant thiol-group-reactive reagents from either side of the cell. These data support the predicted membrane topology of the transport protein by transport measurements. If residues other than the cysteines at positions 429 or 207 are exposed to either side of the plasma membrane by conformational changes, they do not contribute to the transport inhibition by pCMBS. Application of pCMBS to one side of the plasma membrane also inhibited transport from the opposite direction, most likely due to the hindrance of sugar-induced interconversion of transporter conformation.

Polymorphisms of the glucose transporter (GLUT1) gene are associated with diabetic nephropathy

2001 ◽  
Vol 59 (3) ◽  
pp. 985-989 ◽  
Author(s):  
Andrea D. Hodgkinson ◽  
Beverley A. Millward ◽  
Andrew G. Demaine
Keyword(s):  
Diabetic Nephropathy ◽  
Glucose Transporter ◽  
Glucose Transporter Glut1 ◽  
Transporter Glut1 ◽  
Glut1 Gene

scholarly journals Paroxysmal exercise-induced dyskinesia and epilepsy is due to mutations in SLC2A1, encoding the glucose transporter GLUT1

Brain ◽  
2008 ◽  
Vol 131 (7) ◽  
pp. 1831-1844 ◽  
Author(s):  
A. Suls ◽  
P. Dedeken ◽  
K. Goffin ◽  
H. Van Esch ◽  
P. Dupont ◽  
...  
Keyword(s):  
Glucose Transporter ◽  
Exercise Induced ◽  
Glucose Transporter Glut1 ◽  
Transporter Glut1

scholarly journals Monosomy-3 Alters the Expression Profile of the Glucose Transporters GLUT1-3 in Uveal Melanoma

2020 ◽  
Vol 21 (24) ◽  
pp. 9345
Author(s):  
Tjorge Maaßen ◽  
Siranush Vardanyan ◽  
Anton Brosig ◽  
Hartmut Merz ◽  
Mahdy Ranjbar ◽  
...  
Keyword(s):  
Uveal Melanoma ◽  
Glucose Transporter ◽  
Glucose Transporters ◽  
Clinical Factors ◽  
Gene Encoding ◽  
Primary Tumors ◽  
High Affinity ◽  
Monosomy 3 ◽  
Glucose Transporter Glut1 ◽  
Transporter Glut1

Monosomy-3 in uveal melanoma (UM) cells increases the risk of fatal metastases. The gene encoding the low-affinity glucose transporter GLUT2 resides on chromosome 3q26.2. Here, we analyzed the expression of the glucose transporters GLUT1, GLUT2, and GLUT3 with regard to the histological and clinical factors by performing immunohistochemistry on the primary tumors of n = 33 UM patients. UMs with monosomy-3 exhibited a 57% lower immunoreactivity for GLUT2 and a 1.8×-fold higher ratio of GLUT1 to total GLUT1-3. The combined levels of GLUT1-3 proteins were reduced in the irradiated but not the non-irradiated tumors with monosomy-3. GLUT3 expression was stronger in the irradiated samples with disomy-3 versus monosomy-3, but the ratio of the GLUT3 isoform to total GLUT1-3 did not differ with regard to the monosomy-3 status in the irradiated or non-irradiated subgroups. Systemic metastases were associated with the presence of monosomy-3 in the primary and circulating tumor cells as well as a higher GLUT1 ratio. Upregulation of the high-affinity glucose transporter GLUT1 possibly as a compensation for the low-affinity isoform GLUT2 may be enhancing the basal glucose uptake in the UM cells with monosomy-3. Prevention of hyperglycemia might, therefore, be a valuable approach to delay the lethal UM metastases.

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