Rab GTPase family 4 (Rab4). Rab4 subfamily. Rab4 has been implicated in numerous functions within the cell. It helps regulate endocytosis through the sorting, recycling, and degradation of early endosomes. Mammalian Rab4 is involved in the regulation of many surface proteins including G-protein-coupled receptors, transferrin receptor, integrins, and surfactant protein A. Experimental data implicate Rab4 in regulation of the recycling of internalized receptors back to the plasma membrane. It is also believed to influence receptor-mediated antigen processing in B-lymphocytes, in calcium-dependent exocytosis in platelets, in alpha-amylase secretion in pancreatic cells, and in insulin-induced translocation of Glut4 from internal vesicles to the cell surface. Rab4 is known to share effector proteins with Rab5 and Rab11. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.
No pairwise interactions are available for this conserved domain.
Total Mutations Found: 124 Total Disease Mutations Found: 71 This domain occurred 126 times on human genes (225 proteins).
If you've navigated here from a protein, hovering over a position on the weblogo will display the corresponding protein position for that domain position.
The histograms below the weblogo indicate mutations found on the domain. Red is for disease (OMIM) and blue is for SNPs.
Functional Features are displayed as orange boxes under the histograms. You can choose which features are displayed in the box below.
Range on the Protein:
Protein ID Protein Position
Domain Position:
Feature Name:
Total Found:
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