Rab1b overexpression modifies Golgi size and gene expression in HeLa cells and modulates the thyrotrophin response in thyroid cells in culture

NAHUEL ROMERO; CATHERINE I. DUMUR; HERNÁN MARTINEZ ; IRIS A. GARCÍA; PABLO MONETTA; ILEANA SLAVIN; LUCIANA SAMPIERI; NICOLAS KORITSCHONER

MOLECULAR BIOLOGY OF THE CELL

American Society for Cell Biology

Año: 2013 vol. 24 p. 617 - 617

1939-4586

ab1b belongs to the Rab-GTPase family that regulates membrane trafficking and signal transduction systems able to control diverse cellular activities, including gene expression. Rab1b is essential for endoplasmic reticulum?Golgi transport. Although it is ubiquitously expressed, its mRNA levels vary among different tissues. This work aims to characterize the role of the high Rab1b levels detected in some secretory tissues. We report that, in HeLa cells, an increase in Rab1b levels induces changes in Golgi size and gene expression. Significantly, analyses applied to selected genes, KDELR3, GM130 (involved in membrane transport), and the proto-oncogene JUN, indicate that the Rab1b increase acts as a molecular switch to control the expression of these genes at the transcriptional level, resulting in changes at the protein level. These Rab1b-dependent changes require the activity of p38 mitogen-activated protein kinase and the cAMP-responsive element-binding protein consensus binding site