Slc45a1, encoding a glucose transporter protein, is highly expressed in the brain and is implicated in the regulation of glucose homeostasis [5,3,6]. It may play a role in pathways related to brain development and function, and is of great biological importance in maintaining normal cerebral physiologic function [4]. Genetic models can be valuable for studying its function.

In glioblastoma, deletion of Slc45a1, the glucose-proton symporter, was the truncal alteration most significantly associated with the mitochondrial subtype, which had a favorable clinical outcome. Reintroducing Slc45a1 in mitochondrial glioma cells induced acidification and loss of fitness [1]. Mutations in Slc45a1 can cause various neurological disorders. Loss of Slc45a1 in neurons leads to lysosomal dysfunction both in vitro and in vivo, as it plays a dual role in lysosomal sugar transport and stabilization of V1 subunits of the V-ATPase. Its deficiency disrupts iron homeostasis and causes mitochondrial dysfunction [2]. Compound heterozygous variants in Slc45a1 can lead to syndromic intellectual disability by failure of localization on the cell membrane and attenuation of glucose-transporting activity [3]. Recessive mutations in Slc45a1 are associated with intellectual disability and epilepsy, as specific missense variants reduce its intracellular glucose transport activity [4]. A gain-of-function variant due to disruption of a DNA G-quadruplex in Slc45a1 may lead to intellectual developmental disorder with neuropsychiatric features [5].

In summary, Slc45a1 is crucial for glucose transport in the brain and maintaining normal brain function. Its dysregulation, whether through deletion or mutation, is associated with various neurological diseases such as glioblastoma, intellectual disability, and epilepsy. Studies using loss-of-function models have been instrumental in uncovering these associations, providing insights into the underlying molecular mechanisms and potential therapeutic targets for these disorders.

References:

1. Garofano, Luciano, Migliozzi, Simona, Oh, Young Taek, Lasorella, Anna, Iavarone, Antonio. 2021. Pathway-based classification of glioblastoma uncovers a mitochondrial subtype with therapeutic vulnerabilities. In Nature cancer, 2, 141-156. doi:10.1038/s43018-020-00159-4. https://pubmed.ncbi.nlm.nih.gov/33681822/

2. Ghoochani, Ali, Heiby, Julia C, Rawat, Eshaan S, Ori, Alessandro, Abu-Remaileh, Monther. 2024. Cell-Type Resolved Protein Atlas of Brain Lysosomes Identifies SLC45A1-Associated Disease as a Lysosomal Disorder. In bioRxiv : the preprint server for biology, , . doi:10.1101/2024.10.14.618295. https://pubmed.ncbi.nlm.nih.gov/39464040/

3. Zhou, Chiyan, Zhu, Jianjun, Tang, Ping, Zhao, Wei, Liu, Xiaodan. 2024. Compound heterozygous variants in SLC45A1 might cause syndromic intellectual disability by localization failure and activity attenuation in cells. In Clinical genetics, 106, 638-643. doi:10.1111/cge.14588. https://pubmed.ncbi.nlm.nih.gov/39003656/

4. Srour, Myriam, Shimokawa, Noriaki, Hamdan, Fadi F, Al Shamsi, Aisha, Michaud, Jacques L. 2017. Dysfunction of the Cerebral Glucose Transporter SLC45A1 in Individuals with Intellectual Disability and Epilepsy. In American journal of human genetics, 100, 824-830. doi:10.1016/j.ajhg.2017.03.009. https://pubmed.ncbi.nlm.nih.gov/28434495/

5. Chen, Yuxi, Long, Jiang, Wu, Sixian, Zhang, Nannan, Xu, Wenming. . Disruption of a DNA G-quadruplex causes a gain-of-function SCL45A1 variant relevant to developmental disorders. In Acta biochimica et biophysica Sinica, 56, 709-716. doi:10.3724/abbs.2024053. https://pubmed.ncbi.nlm.nih.gov/38655615/

6. Bartölke, Rabea, Heinisch, Jürgen J, Wieczorek, Helmut, Vitavska, Olga. . Proton-associated sucrose transport of mammalian solute carrier family 45: an analysis in Saccharomyces cerevisiae. In The Biochemical journal, 464, 193-201. doi:10.1042/BJ20140572. https://pubmed.ncbi.nlm.nih.gov/25164149/