Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.5.1.18 (glutathione S-transferase)
 22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ADP-ribosylation factor 6 (ARF6) small GTPase functions as a GDP/GTP-regulated switch in the pathways that stimulate actin reorganization and membrane ruffling. The formation of active ARF6GTP is stimulated by guanine nucleotide exchange factors (GEFs) such as cytohesins, which translocate to the plasma membrane in agonist-stimulated cells by binding the lipid second messenger phosphatidylinositol 3,4,5-trisphosphate through the pleckstrin homology domain with subsequent ARF6 activation. Using cytohesin 2 as bait in yeast two-hybrid screening, we have isolated a cDNA encoding a protein termed interaction protein for cytohesin exchange factors 1 (IPCEF1). Using yeast two-hybrid and glutathione S-transferase pull-down assays coupled with deletion mutational analysis, the specific domains required for the cytohesin 2-IPCEF1 interaction were mapped to the coiled-coil domain of cytohesin 2 and the C-terminal 121 amino acids of IPCEF1. IPCEF1 also interacts with the other members of the cytohesin family of ARF GEFs, suggesting that the interaction with IPCEF1 is highly conserved among the cytohesin family of ARF GEFs. The interaction of cytohesin 2 and IPCEF1 in mammalian cells was demonstrated by immunoprecipitation. Immunofluorescence analysis revealed that IPCEF1 co-localizes with cytohesin 2 to the cytosol in unstimulated cells and translocates to the plasma membrane via binding to cytohesin 2 in epidermal growth factor-stimulated cells. However, a deletion mutant of IPCEF1 that lacks the cytohesin 2 binding site failed to co-migrate with cytohesin 2 to the membrane in stimulated cells. The functional significance of the IPCEF1-cytohesin 2 interaction is demonstrated by showing that IPCEF1 increases the in vitro and in vivo stimulation of ARFGTP formation by cytohesin 2.
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PMID:Interaction protein for cytohesin exchange factors 1 (IPCEF1) binds cytohesin 2 and modifies its activity. 1292 Jan 29

IPCEF1 has been reported to interact with ADP-ribosylation factor GTP exchange factors of the cytohesin family and function by modulating the cytohesin 2 activity. This article describes methods used to study the interaction and activation of cytohesin GEFs by IPCEF1. The experimental approaches described here include physical and functional interaction assays by which the association of IPCEF1 with cytohesin 2 is explored both in vitro and in vivo. The methods used to analyze the physical association include GST-pull down and coimmunoprecipitation approaches. We also used yeast two-hybrid and colocalization assays to study the interaction between IPCEF1 and cytohesins. The functional relationship between IPCEF1 and cytohesin 2 was assessed by studying the effect of IPCEF1 on the in vitro and in vivo stimulation of ADP-ribosylation factor 6 GTP formation by cytohesin 2.
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PMID:Analysis of the interaction between cytohesin 2 and IPCEF1. 1641 75