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Protein GDI1 PDB 1d5t.png
Aliases GDI1, 1A, GDIL, MRX41, MRX48, OPHN2, RABGD1A, RABGDIA, XAP-4, GDP dissociation inhibitor 1
External IDs MGI: 99846 HomoloGene: 37487 GeneCards: GDI1
RNA expression pattern
PBB GE GDI1 201864 at fs.png
More reference expression data
Species Human Mouse
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC) Chr X: 154.44 – 154.44 Mb Chr X: 74.3 – 74.31 Mb
PubMed search [1] [2]
View/Edit Human View/Edit Mouse

Rab GDP dissociation inhibitor alpha is a protein that in humans is encoded by the GDI1 gene.[3][4]


GDP dissociation inhibitors are proteins that regulate the GDP-GTP exchange reaction of members of the rab family, small GTP-binding proteins of the ras superfamily, that are involved in vesicular trafficking of molecules between cellular organelles. GDIs slow the rate of dissociation of GDP from rab proteins and release GDP from membrane-bound rabs. GDI1 is expressed primarily in neural and sensory tissues. Mutations in GDI1 have been linked to X-linked nonspecific mental retardation.[5]

Rab GTPases cycles between the cytosolic compartment, where it is bound to a protein called GDI (GDP Dissociation Inhibitor), and the membrane, where it interacts with a receptor, a nucleotide exchange factor, a GAP (GTPase Activating Protein) and probably other factors that link it to the appropriate SNARE. GDI is non-specific with respect to the rab it binds. However, the exchanger, receptor and GAP, are rab specific.


GDI1 has been shown to interact with CDC42.[6]


  1. ^ "Human PubMed Reference:". 
  2. ^ "Mouse PubMed Reference:". 
  3. ^ Bächner D, Sedlacek Z, Korn B, Hameister H, Poustka A (Sep 1995). "Expression patterns of two human genes coding for different rab GDP-dissociation inhibitors (GDIs), extremely conserved proteins involved in cellular transport". Hum. Mol. Genet. 4 (4): 701–8. doi:10.1093/hmg/4.4.701. PMID 7543319. 
  4. ^ Sedlacek Z, Konecki DS, Korn B, Klauck SM, Poustka A (Mar 1995). "Evolutionary conservation and genomic organization of XAP-4, an Xq28 located gene coding for a human rab GDP-dissociation inhibitor (GDI)". Mamm. Genome. 5 (10): 633–9. doi:10.1007/BF00411459. PMID 7849400.  Check date values in: |year= / |date= mismatch (help)
  5. ^ "Entrez Gene: GDI1 GDP dissociation inhibitor 1". 
  6. ^ Gibson RM, Wilson-Delfosse AL (Oct 2001). "RhoGDI-binding-defective mutant of Cdc42Hs targets to membranes and activates filopodia formation but does not cycle with the cytosol of mammalian cells". Biochem. J. 359 (Pt 2): 285–94. doi:10.1042/0264-6021:3590285. PMC 1222146Freely accessible. PMID 11583574. 

Further reading[edit]