Rab GTPase family 28 (Rab28). Rab28 subfamily. First identified in maize, Rab28 has been shown to be a late embryogenesis-abundant (Lea) protein that is regulated by the plant hormone abcisic acid (ABA). In Arabidopsis, Rab28 is expressed during embryo development and is generally restricted to provascular tissues in mature embryos. Unlike maize Rab28, it is not ABA-inducible. Characterization of the human Rab28 homolog revealed two isoforms, which differ by a 95-base pair insertion, producing an alternative sequence for the 30 amino acids at the C-terminus. The two human isoforms are presumably the result of alternative splicing. Since they differ at the C-terminus but not in the GTP-binding region, they are predicted to be targeted to different cellular locations. 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.
No pairwise interactions are available for this conserved domain.
Total Mutations Found: 124 Total Disease Mutations Found: 73 This domain occurred 98 times on human genes (173 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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