ID Q4R8X3; PN Ras-related protein Rab-1B; GN RAB1B; OS 9541; SL Nucleus Position: SL-0198; SL Comments: Cytoplasm {ECO:0000250|UniProtKB:P10536}. Membrane {ECO:0000250|UniProtKB:P10536}; Lipid-anchor {ECO:0000250|UniProtKB:P10536}; Cytoplasmic side {ECO:0000250|UniProtKB:P10536}. Preautophagosomal structure membrane {ECO:0000250|UniProtKB:Q9H0U4}; Lipid-anchor {ECO:0000250|UniProtKB:P10536}; Cytoplasmic side {ECO:0000250|UniProtKB:P10536}. Cytoplasm, perinuclear region {ECO:0000250|UniProtKB:P10536}. Note=Targeted by REP1 to membranes of specific subcellular compartments including endoplasmic reticulum, Golgi apparatus, and intermediate vesicles between these two compartments. In the GDP-form, colocalizes with GDI in the cytoplasm (By similarity). Co-localizes with MTMR6 to the endoplasmic reticulum- Golgi intermediate compartment and to the peri-Golgi region (By similarity). {ECO:0000250|UniProtKB:P10536, ECO:0000250|UniProtKB:Q9H0U4}. DR UNIPROT: Q4R8X3; DR Pfam: PF00071; DR PROSITE: PS51419; DE Function: The small GTPases Rab are key regulators of intracellular membrane trafficking, from the formation of transport vesicles to their fusion with membranes. Rabs cycle between an inactive GDP-bound form and an active GTP-bound form that is able to recruit to membranes different set of downstream effectors directly responsible for vesicle formation, movement, tethering and fusion (By similarity). Plays a role in the initial events of the autophagic vacuole development which take place at specialized regions of the endoplasmic reticulum (By similarity). Regulates vesicular transport between the endoplasmic reticulum and successive Golgi compartments. Required to modulate the compacted morphology of the Golgi. Promotes the recruitment of lipid phosphatase MTMR6 to the endoplasmic reticulum-Golgi intermediate compartment (By similarity). {ECO:0000250|UniProtKB:P10536, ECO:0000250|UniProtKB:Q9H0U4}. DE Reference Proteome: Yes; GO GO:0048471; GO GO:0034045; GO GO:0003925; GO GO:0005525; GO GO:0006914; GO GO:0007030; GO GO:0015031; TP Membrane Topology: Lipid-Anchored; Source: UniProt - By Similarity {ECO:0000250|UniProtKB:Q9H0U4}; SQ MNPEYDYLFKLLLIGDSGVGKSCLLLRFADDTYTESYISTIGVDFKIRTIELDGKTIKLQIWDTAGQERFRTITSSYYRG SQ AHGIIVVYDVTDRESYANVKQWLQEIDRYASENVNKLLVGNKSDLTTKKVVDNTTAKEFADSLGIPFLETSAKNATNVEQ SQ AFMTMAAEIKKRMGPGAASGGERPNLKIDSTPVKPAGGGCC //