Cytoplasmic retention sites in p190RhoGEF confer anti-apoptotic activity to an EGFP-tagged protein.

Journal article

p190RhoGEF is a large multi-functional protein with guanine nucleotide exchange (GEF) activity. The C-terminal region of p190RhoGEF is a highly interactive domain that binds multiple factors, including proteins with anti-apoptotic activities. We now report that transfection of EGFP-tagged p190RhoGEF protects Neuro 2a cells from stress-induced apoptosis and that anti-apoptotic activity is localized to cytoplasmic retention sequences (CRS-1 and CRS-2) in the C-terminal region of p190RhoGEF. Cytoplasmic retention is conferred to an EGFP fluorescent marker when fused to either CRS-1 or CRS-2. Both cytoplasmic retention and anti-apoptotic activity are lost by deleting CRS-1 and CRS-2 in the p190RhoGEF sequence and can be recovered by restoring either CRS-1 or CRS-2 to the EGFP-tagged sequence. Since the CRS-1 and CRS-2 contain the JIP-1 and 14-3-3 binding sites, we propose that anti-apoptotic activity may be conferred by the binding of p190RhoGEF to JIP-1 or 14-3-3, possibly by altering their interactive properties or nucleocytoplasmic movements. Taken together, our findings support a model whereby multiple interactions of p190RhoGEF confer homeostatic properties to differentiated neurons and may link neuronal homeostasis to the regulation of NF-L expression.

Authors: Wu, J; Zhai, J; Lin, H; Nie, Z; Ge, W

• Publication status: Published
• Journal: Brain research. Molecular brain research
• Volume: 117
• Issue: 1
• Pages: 27-38
• Publication date: 2003-09-01
• DOI: 10.1016/s0169-328x(03)00263-8
• ISSN: 0169-328X
• Language: English
• Keywords: Animals; Cytoplasm; Cell Death; Microscopy, Confocal; Blotting, Western; Proto-Oncogene Proteins c-myc; Intracellular Signaling Peptides and Proteins; Luminescent Proteins; Peptide Fragments; Apoptosis; Protein Binding; Glutathione Transferase; Guanine Nucleotide Exchange Factors; Precipitin Tests; DNA-Binding Proteins; Green Fluorescent Proteins; Binding Sites; Repressor Proteins; Nuclear Proteins; Cell Aggregation; Carrier Proteins; Cell Line; Transfection; In Situ Nick-End Labeling; Sequence Homology, Amino Acid; Two-Hybrid System Techniques; GTPase-Activating Proteins