NCBI Summary:
This gene encodes a major glucose transporter in the mammalian blood-brain barrier. The encoded protein is found primarily in the cell membrane and on the cell surface, where it can also function as a receptor for human T-cell leukemia virus (HTLV) I and II. Mutations in this gene have been found in a family with paroxysmal exertion-induced dyskinesia. [provided by RefSeq, Apr 2013]
General function
Channel/transport protein
Comment
Cellular localization
Plasma membrane
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Ovarian function
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Expression regulated by
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Ovarian localization
Oocyte
Comment
Multiple facilitated glucose transporters SLC2As are required for normal mouse preimplantation embryo development. Arhin SK et al. (2019) Glucose metabolism is an essential energy source for mammalian preimplantation embryonic development. Therefore, we aimed to analyze the expression of all 12 known glucose transporters (facilitated solute carrier family 2, Slc2a) during early mouse embryo development. Gene and protein expression of Slc2a transporters in oocytes and embryos were assessed by the TaqMan gene expression assay and confocal immunofluorescence, respectively. Except for Slc2a2, the other 11 Slc2a transcripts were detected in oocytes. Transcripts of Slc2a1, Slc2a3, Slc2a4, and Slc2a8 were the most enriched and detected in preimplantation embryos. The transcription of other Slc2a isoforms was barely detectable or absent after fertilization; however, they were detected in blastocysts, except for Slc2a10 and Slc2a13. Embryo culture in the simple defined medium caused a reduction in transcription of Slc2a1, Slc2a3, Slc2a4, and Slc2a8 in blastocyst; yet, amino acids partially reversed this impaired transcription of Slc2a1 and Slc2a4. SLC2A1 and SLC2A4 proteins were detected at all embryonic stages with nuclear accumulation in the embryos at the early cleavage stage. SLC2A3 and SLC2A8 were not detected in embryos until the eight-cell stage. The cellular membrane localization of SLC2A1, SLC2A3, and SLC2A8 occurred after compaction and was characterized in blastocysts. SLC2A4 was evenly distributed in the cytoplasm and nuclei without its characteristic membrane localization. Indinavir sulfate (a SLC2A4 inhibitor) decreased the rate of development and prevented glucose utilization in embryos after compaction. These inhibitory activities were partially reversed by exogenous insulin. The results unveil distinct expression patterns of individual Slc2a glucose transporters during early embryo development. Taken together, they provide novel insights into the understanding and management of glucose metabolic infertility in assisted-reproductive technologies (ART).//////////////////
Follicle stages
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Phenotypes
Mutations
1 mutations
Species: mouse
Mutation name: None
type: null mutation fertility: fertile Comment: A mouse model for Glut-1 haploinsufficiency. Wang D et al. Glut-1 deficiency syndrome (Glut-1 DS, OMIM #606777) is characterized by infantile seizures, developmental delay, acquired microcephaly and hypoglycorrhachia. It is caused by haploinsufficiency of the blood-brain barrier hexose carrier. Heterozygous mutations or hemizygosity of the GLUT-1 gene cause Glut-1 DS. We generated a heterozygous haploinsufficient mouse model by targeted disruption of the promoter and exon 1 regions of the mouse GLUT-1 gene. GLUT-1+/- mice have epileptiform discharges on electroencephalography (EEG), impaired motor activity, incoordination, hypoglycorrhachia, microencephaly, decreased brain glucose uptake as measured by positron emission tomography (PET) scan and decreased brain Glut-1 expression by western blot (66%). The GLUT-1+/- murine phenotype mimics the classical human presentation of Glut-1 DS. This GLUT-1+/- mouse model creates an opportunity to investigate Glut-1 function, to examine the pathophysiology of Glut-1 DS in vivo and to evaluate new treatment strategies.