RIC8A

Cilia effects upon perturbation of RIC8A

Cilia number / % ciliated:

Decreased cilia number

Loss-of-function effect:

Impaired ciliogenesis

Overexpression effect:

Unknown

Ciliogenesis screen results (1 screens)

• Wheway et al. 2015 (siRNA) [siRNA]: Ciliogenesis Defect (z=-3.97) PMID:26167766

Phenotypes

Mouse phenotype:

persistence of hyaloid vascular system

Subcellular localization

cilia, cytosol, Plasma membrane

References: PMID:37910589

Functional category

• G protein signaling
• Cilium signaling
• Ciliary assembly/disassembly
• Cilia–cytoskeleton/adhesion links

Function

RIC-8 is a highly conserved non-canonical guanine nucleotide exchange factor that binds monomeric GDP-bound Galpha subunits and catalyses GTP exchange independently of GPCRs. Mammals encode two paralogs (RIC8A: Galpha-i/q/12/13; RIC8B: Galpha-s/olf). C. elegans RIC-8 localizes to the inversin compartment of channel cilia and depends on intraflagellar transport for ciliary entry, with an RVxP motif and intact transition zone required for proper distribution; loss of ric-8 in C. elegans reduces wing cilia length in AWA, AWB, AWC sensory neurons. Campagna et al. 2026 reported that human RIC8A and RIC8B are required for ciliogenesis in RPE-1 cells (preprint figures pending direct review).