rab-33 Antibody

Rab33 Protein Overview

Rab33 proteins (Rab33A and Rab33B) are small GTPases regulating vesicular transport. Key characteristics include:

Role in Autophagy

• Rab33B binds Atg16L1 to regulate autophagosome formation. Mutations (e.g., Atg16L1 T168A) abolish this interaction, impairing autophagy initiation .

• Co-immunoprecipitation studies confirm Rab33B preferentially interacts with GTP-bound Atg16L1 .

Role in Cell Migration and Secretion

• Focal Adhesion Dynamics: Rab33B depletion via siRNA increases cell migration velocity by 20% and reduces focal adhesion (FA) size by 20%, while accelerating FA disassembly by 40% .

• Exocyst Interaction: Rab33B recruits Exoc6 to secretory vesicles, mediating β1-integrin delivery to FAs. Rab33B knockdown reduces Exoc6-positive vesicles at leading edges by 25% .

• Cancer Relevance: Rab33B expression inversely correlates with lung cancer progression and metastasis (TCGA data) .

Experimental Applications of Rab-33 Antibodies

• Localization Studies: Immunofluorescence confirms Rab33B’s Golgi and secretory vesicle localization .

• Functional Assays: Antibodies enable validation of Rab33B’s role in FA dynamics through siRNA rescue experiments (e.g., GFP-Rab33B restores migration rates) .

• Protein Interaction Analysis: Co-immunoprecipitation identifies Rab33B’s binding partners (Atg16L1, Exoc6) and GTPase activity dependence .

Key Data from Rab33 Studies

Technical Considerations

• Antibody Specificity: Rab33 antibodies must distinguish between Rab33A and Rab33B due to their 55.3% sequence homology .

• Functional Mutants: Point mutants (e.g., Rab33B T47N) are used to study GTPase activity in pull-down assays .