High impact information on RHO4

• Bnr1p interacts with another Rho family member, Rho4p, but not with Rho1p [1].
• Overproduction of either Rho3p or the Rho3p-related GTPase Rho4p suppressed the boi defect [2].
• We found here that a novel Src homology 3 (SH3) domain-containing protein, encoded by YMR032w, interacted with Bnr1p in a GTP-Rho4p-dependent manner through the FH1 domain of Bnr1p and the SH3 domain of Ymr032wp [3].
• In addition, these results strongly argue in favour of Rho3p and Rho4p being the targets of Rgd1p RhoGAP activity in vivo [4].
• We hypothesize that the rgd1Delta inactivation, at least through the hyperactivation of the small GTPases Rho3p and Rho4p, alters the secretory pathway and/or the actin cytoskeleton and decreases activity of the PKC pathway [5].

Biological context of RHO4

• Rho3p and Rho4p are involved in regulating cell polarity by controlling polarized exocytosis [6].
• This approach was used for the complete deletion of the open reading frame of the A. gossypii RHO4 gene for which a double-strand sequence was available as information source for the design of PCR primers [7].
• Deletion of RHO4 did not affect cell growth, but deletion of RHO3 caused a severe growth delay and a decrease in cell viability [8].
• We have isolated two novel genes, designated as RHO3 (on chromosome IX) and RHO4 (on chromosome XI), belonging to the ras superfamily, from the yeast Saccharomyces cerevisiae [8].
• The RhoGAP Rgd1p is involved in different signal transduction pathways in Saccharomyces cerevisiae through its regulatory activity upon the Rho3 and Rho4 GTPases [9].

Physical interactions of RHO4

• The Rho3 and Rho4 small GTPases interact functionally with Wsc1p, a cell surface sensor of the protein kinase C cell-integrity pathway in Saccharomyces cerevisiae [6].

Other interactions of RHO4

• Analysis of the synthetic lethal phenomenon revealed that production of activated Rho3p and Rho4p leads to lethality in wsc1Delta cells [6].

References