SAR1B — Secretion associated Ras related GTPase 1B
SAR1B belongs to a gene co-expression module in 4 of 28 SCUBA cell types. Each module groups genes that rise and fall together in that cell type; the genes it shares a module with are its closest co-expression partners there.
SAR1B's module in each cell type
| Cell type | Module | Shares the module with | |
|---|---|---|---|
| CD4⁺ T cells | Lipid Metabolism Housekeeping | ANXA7, AP2B1, ASNSD1, C1D, CAPZA2, ECHDC1, EIF3A, GRSF1 +3 more | View in SCUBA |
| Enterocytes | Enterocyte lipid trafficking Lipid metabolism | CYP2J2, DYRK2, LPCAT3, MSRA, RAB17, RHOU, TGOLN2, UGCG | View in SCUBA |
| Innate lymphoid cells | RNA Chromatin Regulation RNA processing & translation | ACADM, AURKAIP1, BUD23, CBX3, CMC2, COPB1, DNAJA2, DYNC1LI1 +19 more | View in SCUBA |
| Macrophages | Actin Cytoskeleton Organization Cytoskeletal | ACTR3, ARF1, ARHGDIA, ARPC4, CDC42, DERL1, EIF4G2, GARS1 +20 more | View in SCUBA |
About the gene
| Synonyms | SARA2 |
|---|---|
| Chromosome | 5: 134601149-134649271 |
| Predicted location | Intracellular |
| Essential gene | No |
| Protein class | Disease related genes, Human disease related genes, Plasma proteins, Predicted intracellular proteins |
| Molecular function | Hydrolase |
| Biological process | ER-Golgi transport, Protein transport, Transport |
Function
Small GTPase that cycles between an active GTP-bound and an inactive GDP-bound state and mainly functions in vesicle-mediated endoplasmic reticulum (ER) to Golgi transport. The active GTP-bound form inserts into the endoplasmic reticulum membrane where it recruits the remainder of the coat protein complex II/COPII. The coat protein complex II assembling and polymerizing on endoplasmic reticulum membrane is responsible for both the sorting of cargos and the deformation and budding of membranes into vesicles destined to the Golgi. In contrast to SAR1A, SAR1B specifically interacts with the cargo receptor SURF4 to mediate the transport of lipid-carrying lipoproteins including APOB and APOA1 from the endoplasmic reticulum to the Golgi and thereby, indirectly regulates lipid homeostasis. In addition to its role in vesicle trafficking, can also function as a leucine sensor regulating TORC1 signaling and more indirectly cellular metabolism, growth and survival. In absence of leucine, interacts with the GATOR2 complex via MIOS and inhibits TORC1 signaling. The binding of leucine abrogates the interaction with GATOR2 and the inhibition of the TORC1 signaling. This function is completely independent of the GTPase activity of SAR1B.
Human Protein Atlas · Open Targets · UniProt
Gene annotation from the Human Protein Atlas and UniProt; see sources & licences.