Alternative Splicing and Cleavage of GLUT8
| Autor: | Elias Oxman, Ildiko Kasza, Joshua A. Martin, Katherine A. Senn, Caroline M. Alexander, Heidi Dvinge |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
GLUT8
Population Glucose Transport Proteins Facilitative Endosomes 03 medical and health sciences 0302 clinical medicine Cell Line Tumor Homeostasis Humans RNA Messenger education Molecular Biology Cells Cultured 030304 developmental biology Glucose Transporter Type 1 0303 health sciences education.field_of_study Messenger RNA biology Alternative splicing Glucose transporter Transporter Cell Biology Cell biology Alternative Splicing Glucose 030220 oncology & carcinogenesis RNA splicing biology.protein GLUT1 Lysosomes Research Article |
| Zdroj: | Mol Cell Biol |
| ISSN: | 1098-5549 |
| Popis: | The GLUT (SLC2) family of membrane-associated transporters are described as glucose transporters. However, this family is divided into three classes and, though the regulated transporter activity of class I proteins is becoming better understood, class III protein functions continue to be obscure. We have cataloged the relative expression and splicing of SLC2 mRNA isomers in tumors and normal tissues, with a focus on breast tumors and cell lines. mRNA for the class III protein GLUT8 is the predominant SLC2 species expressed alongside GLUT1 in many tissues, but GLUT8 mRNA exists mostly as an untranslated splice form in tumors. We confirm that GLUT8 is not presented at the cell surface and does not transport glucose directly. However, we reveal a lysosome-dependent reaction that cleaves the GLUT8 protein and releases the carboxy-terminal peptide to a separate vesicle population. Given the localization of GLUT8 at a major metabolic hub (the late endosomal/lysosomal interface) and its regulated cleavage reaction, we evaluated TXNIP-mediated hexosamine homeostasis and speculate that GLUT8 may function as a sensory component of this reaction. |
| Databáze: | OpenAIRE |
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