GLUT8

Last updated
solute carrier family 2, (facilitated glucose transporter) member 8
Identifiers
SymbolSLC2A8
Alt. symbolsGLUTX1, GLUT8
NCBI gene 29988
HGNC 13812
OMIM 605245
RefSeq NM_014580
Other data
Locus Chr. 9 q33.3

GLUT8 also known as SLC2A8 is the eighth member of glucose transporter superfamily. [1]

Contents

It is characterized by the presence of two leucine residues in its N-terminal intracellular domain, which influences intracellular trafficking. [2]

Discovery

GLUT8, originally named GLUTX1, was cloned almost simultaneously by two different groups. [2] [3]

Tissue distribution

Subcellular localization

Contrary to GLUT4, GLUT8 (previously known as GLUTX1) is not insulin-sensitive.[ citation needed ] In other words, insulin does not promote GLUT8 translocation to the cell surface in neurons as well as in transfected cell lines.[ citation needed ]

Where in the cell GLUT8 is localized in not yet clear. Most GLUT8 is not present at the cell surface. Some co-localization with both the endoplasmic reticulum and late endosomes/lysosomes has been published. [4]

When the N-terminal di-leucine motif is mutated into a di-alanine motif, GLUT8 is located mostly at the cell surface in Xenopus oocytes and mammalian cells such as HEK 293 cells and differentiated PC12 cells.[ citation needed ]

Physiological role

GLUT8 function in vivo remains to be defined, despite suggestions that it may play a role in fertility, being expressed at high levels in testes and in the acrosomal part of spermatozoa. [5] Furthermore, GLUT8 appears to play an important role in the energy metabolism of sperm cells. [6]

GLUT8, when expressed in Xenopus oocytes, mediates glucose uptake with high affinity. Other hexoses are not good substrates of the transporter.

Mice devoid of both copies of the SLC2A8 gene are viable, fertile and do not show any obvious phenotype. [7] They are not diabetic, showing that GLUT8 is unlikely to play major roles in glucose homeostasis.[ citation needed ]

Related Research Articles

Glucose transporter 2 (GLUT2) also known as solute carrier family 2, member 2 (SLC2A2) is a transmembrane carrier protein that enables protein facilitated glucose movement across cell membranes. It is the principal transporter for transfer of glucose between liver and blood Unlike GLUT4, it does not rely on insulin for facilitated diffusion.

Glucose transporter

Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose across the plasma membrane, a process known as facilitated diffusion. Because glucose is a vital source of energy for all life, these transporters are present in all phyla. The GLUT or SLC2A family are a protein family that is found in most mammalian cells. 14 GLUTS are encoded by human genome. GLUT is a type of uniporter transporter protein.

Glucose transporter type 4 (GLUT-4), also known as solute carrier family 2, facilitated glucose transporter member 4, is a protein encoded, in humans, by the SLC2A4 gene. GLUT4 is the insulin-regulated glucose transporter found primarily in adipose tissues and striated muscle. The first evidence for this distinct glucose transport protein was provided by David James in 1988. The gene that encodes GLUT4 was cloned and mapped in 1989.

Glucose transporter 1, also known as solute carrier family 2, facilitated glucose transporter member 1 (SLC2A1), is a uniporter protein that in humans is encoded by the SLC2A1 gene. GLUT1 facilitates the transport of glucose across the plasma membranes of mammalian cells. 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. One good source of GLUT1 is erythrocyte membranes. GLUT1 accounts for 2 percent of the protein in the plasma membrane of erythrocytes. GLUT1, found in the plasma membrane of erythrocytes, is a classic example of a uniporter. After glucose is transported into the erythrocyte, it is rapidly phosphorylated, forming glucose-6-phosphate, which cannot leave the cell. Mutations in this gene can cause GLUT1 deficiency syndrome 1, GLUT1 deficiency syndrome 2, idiopathic generalized epilepsy 12, dystonia 9, and stomatin-deficient cryohydrocytosis.

Leucyl/cystinyl aminopeptidase

Leucyl/cystinyl aminopeptidase, also known as cystinyl aminopeptidase (CAP), insulin-regulated aminopeptidase (IRAP), human placental leucine aminopeptidase (PLAP), oxytocinase, and vasopressinase, is an enzyme of the aminopeptidase group that in humans is encoded by the LNPEP gene.

Zinc transporter 8

Zinc transporter 8 (ZNT8) is a protein that in humans is encoded by the SLC30A8 gene. ZNT8 is a zinc transporter related to insulin secretion in humans. Certain alleles of the SLC30A8 gene may increase the risk for developing type 2 diabetes, but a loss-of-function mutation appears to greatly reduce the risk of diabetes.

Glucose transporter 3, also known as solute carrier family 2, facilitated glucose transporter member 3 (SLC2A3) is a protein that in humans is encoded by the SLC2A3 gene. GLUT3 facilitates the transport of glucose across the plasma membranes of mammalian cells. GLUT3 is most known for its specific expression in neurons and has originally been designated as the neuronal GLUT. GLUT3 has been studied in other cell types with specific glucose requirements, including sperm, preimplantation embryos, circulating white blood cells and carcinoma cell lines.

Neutral and basic amino acid transport protein rBAT

Neutral and basic amino acid transport protein rBAT is a protein that in humans is encoded by the SLC3A1 gene.

Sodium/glucose cotransporter 1

Sodium/glucose cotransporter 1 (SGLT1) also known as solute carrier family 5 member 1 is a protein in humans that is encoded by the SLC5A1 gene which encodes the production of the SGLT1 protein to line the absorptive cells in the small intestine and the epithelial cells of the kidney tubules of the nephron for the purpose of glucose uptake into cells. Through the use of the sodium glucose cotransporter 1 protein, cells are able to obtain glucose which is further utilized to make and store energy for the cell.

GLUT5

GLUT5 is a fructose transporter expressed on the apical border of enterocytes in the small intestine. GLUT5 allows for fructose to be transported from the intestinal lumen into the enterocyte by facilitated diffusion due to fructose's high concentration in the intestinal lumen. GLUT5 is also expressed in skeletal muscle, testis, kidney, fat tissue (adipocytes), and brain.

Actinin alpha 1

Alpha-actinin-1 is a protein that in humans is encoded by the ACTN1 gene.

Concentrative nucleoside transporter 1

Concentrative nucleoside transporter 1 (CNT1) is a protein that in humans is encoded by the SLC28A1 gene.

SLC2A10

Solute carrier family 2, facilitated glucose transporter member 10 is a protein that in humans is encoded by the SLC2A10 gene.

SLC2A12

Solute carrier family 2, facilitated glucose transporter member 12 is a protein that in humans is encoded by the SLC2A12 gene.

SLC2A6

Solute carrier family 2, facilitated glucose transporter member 6 is a protein that in humans is encoded by the SLC2A6 gene.

SLC2A9

Solute carrier family 2, facilitated glucose transporter member 9 is a protein that in humans is encoded by the SLC2A9 gene.

SLC2A7

Solute carrier family 2, facilitated glucose transporter member 7 also known as glucose transporter 7 (GLUT7) is a protein that in humans is encoded by the SLC2A7 gene.

SLC2A11

Solute carrier family 2, facilitated glucose transporter member 11 (SLC2A11) also known as glucose transporter type 10/11 (GLUT-10/11) is a protein that in humans is encoded by the SLC2A11 gene.

SLC2A14

Solute carrier family 2, member 14 is a protein that in humans is encoded by the SLC2A14 gene.

TUG-UBL1 protein domain

In molecular biology, TUG-UBL1 refers to a protein that regulates a glucose transporter called GLUT4. TUG-UBL1 is an acronym for Tether containing UBX domain for GLUT4-Ubiquitin Like 1, this is encoded for by the gene, ASPSCR1.

References

  1. Uldry M, Thorens B (February 2004). "The SLC2 family of facilitated hexose and polyol transporters" (PDF). Pflügers Arch. 447 (5): 480–9. doi:10.1007/s00424-003-1085-0. PMID   12750891. S2CID   25539725.
  2. 1 2 Ibberson M, Uldry M, Thorens B (2000). "GLUTX1, a novel mammalian glucose transporter expressed in the central nervous system and insulin-sensitive tissues". J. Biol. Chem. 275 (7): 4607–12. doi: 10.1074/jbc.275.7.4607 . PMID   10671487.
  3. Doege H, Schürmann A, Bahrenberg G, Brauers A, Joost HG (2000). "GLUT8, a novel member of the sugar transport facilitator family with glucose transport activity". J. Biol. Chem. 275 (21): 16275–80. doi: 10.1074/jbc.275.21.16275 . PMID   10821868.
  4. Widmer M, Uldry M, Thorens B (2005). "GLUT8 subcellular localization and absence of translocation to the plasma membrane in PC12 cells and hippocampal neurons". Endocrinology. 146 (11): 4727–36. doi: 10.1210/en.2005-0668 . PMID   16109784.
  5. Schürmann A, Axer H, Scheepers A, Doege H, Joost HG (February 2002). "The glucose transport facilitator GLUT8 is predominantly associated with the acrosomal region of mature spermatozoa". Cell Tissue Res. 307 (2): 237–42. doi:10.1007/s00441-001-0499-2. PMID   11845330. S2CID   20138373.
  6. Gawlik V, Schmidt S, Scheepers A, Wennemuth G, Augustin R, Aumüller G, Moser M, Al-Hasani H, Kluge R, Joost HG, Schürmann A (April 2008). "Targeted disruption of Slc2a8 (GLUT8) reduces motility and mitochondrial potential of spermatozoa". Mol. Membr. Biol. 25 (3): 224–35. doi:10.1080/09687680701855405. PMC   2557070 . PMID   18428038.
  7. Membrez M, Hummler E, Beermann F, Haefliger JA, Savioz R, Pedrazzini T, Thorens B (2006). "GLUT8 is dispensable for embryonic development but influences hippocampal neurogenesis and heart function". Mol. Cell. Biol. 26 (11): 4268–76. doi:10.1128/MCB.00081-06. PMC   1489108 . PMID   16705176.