Inhibition of GEF-H1-RhoA signaling in inflammation with a stapled peptide mimicry of the RhoA67-78 helix

Abstract

Guanine exchange factors (GEFs) are considered hard to drug with conventional small molecules, they lack conventional deep binding pockets and binding ligands are seldom reported. Here we report the design of a stapled peptide stP5 targeting the interaction between cytoskeletal regulator RhoA GTPase and its activator guanine exchange factor H1 (GEF-H1). StP5 is a modified RhoA mimic based on a previously identified bioactive -helical epitope to GEF-H1. StP5 effectively inhibits GEF-H1-induced morphological and transcriptional changes in cellular models for inflammation and does not affect the related GEF p114RhoGEF (ARHGEF18). StP5 peptide is approximately 100 fold more active in cellular assays than the unstapled P5 peptide. We provide a bioinformatic analysis of the stP5 bindings site in different GEFs, providing a basis for this selectivity. The GEF-H1 inhibitor stP5 represents a step towards fully drugging GEF-H1. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=102 SRC="FIGDIR/small/624118v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@d783b3org.highwire.dtl.DTLVardef@10798b2org.highwire.dtl.DTLVardef@1ba0817org.highwire.dtl.DTLVardef@693367_HPS_FORMAT_FIGEXP M_FIG C_FIG