Glycolipid transfer protein knockout disrupts vesicle trafficking to the plasma membrane

• Published in: The Journal of biological chemistry Vol. 299; no. 4; p. 104607
• Main Authors: Nurmi, Henrik, Backman, Anders P.E., Halin, Josefin, Lönnfors, Max, Blom, Tomas, Roos-Mattjus, Pia, Mattjus, Peter
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2023; American Society for Biochemistry and Molecular Biology
• Subjects: Biological Transport - genetics; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell Membrane - metabolism; Cell Movement - genetics; Cytosol - metabolism; endoplasmic reticulum (ER); Gene Expression Regulation - genetics; Gene Knockout Techniques; gene silencing; glycerosphingolipid; glycolipid; Golgi; HeLa Cells; Humans; intracellular trafficking; lipid transport; Protein Binding - genetics; sphingolipid; VAP-A; VSVG; GLTP; glycolipid; VAP-A; VAP; sphingolipid; VSVG; gene silencing; lipid transport; GO; intracellular trafficking; glycerosphingolipid; ER; gRNA; DMEM; GSLs; Golgi; cDNA; endoplasmic reticulum (ER); ERES; MCS; OCR
• ISSN: 0021-9258; 1083-351X; 1083-351X
• DOI: 10.1016/j.jbc.2023.104607

The glycolipid transfer protein (GLTP) has been linked to many cellular processes aside from its best-known in vitro function as a lipid transport protein. It has been proposed to act as a sensor and regulator of glycosphingolipid homeostasis in cells. Furthermore, through its previously determined interaction with the endoplasmic reticulum membrane protein VAP-A (vesicle-associated membrane protein-associated protein A), GLTP may also be involved in facilitating vesicular transport in cells. In this study, we characterized the phenotype of CRISPR/Cas9-mediated GLTP KO HeLa cells. We showed that motility, three-dimensional growth, and cellular metabolism were all altered by GLTP knockout. Expression of a GLTP mutant incapable of binding VAP disrupted cell spheroid formation, indicating that the GLTP–VAP interaction is linked to cellular adhesion, cohesion, and three-dimensional growth. Most notably, we found evidence that GLTP, through its interaction with VAP-A, affects vesicular trafficking, marking the first cellular process discovered to be directly impacted by a change in GLTP expression.