Rab GTPases cycle between GDP and GTP bound forms. Rab1 localizes in the ER-Golgi intermediate compartment and is essential for ER to Golgi transport. Expression of a Rab1 mutant with impaired GTPase activity (Rab1Q67L) induces enlargement of the Golgi compartment. To explore how cells respond to Rab1-regulated Golgi enlargement we performed a global gene expression microarray analysis on cells expressing Rab1 constructs. RNA isolation, quantification, assessment of RNA integrity, labeling and hybridization procedures compatible with the Affymetrix GeneChip® platform were performed on samples from control cells (expressing GFP empty vector, or GFP-Rab7Q67L) and from cells expressing GFP-Rab1wt and GFP-Rab1Q67L. Thus, we identified genes with significant changes (P<0.05) in expression levels, encoding for proteins that might be involved in Rab1-regulated pathways (i.e. specific transport proteins; transcription factors, phosphatases-kinases and others). Our study shows specific Rab1-dependent changes of gene transcription.  Additional analysis will provide information of the possible mechanisms that allow cells adaptation to an increase in Rab1 activity and will permit to establish a correlation with physiological situations where Rab1 is highly expressed.