Disease relevance of Rgs9bp

• In the chicken, R9AP appears to be expressed in a variety of neuronal tissues, particularly in sensory cells including inner ear hair cells, photoreceptors, and dorsal root ganglion neurons [1].

High impact information on Rgs9bp

• R9AP, a membrane anchor for the photoreceptor GTPase accelerating protein, RGS9-1 [2].
• In photoreceptors R9AP regulates several critical properties of RGS9 including its intracellular targeting, stability and catalytic activity [3].
• Both R7BP and R9AP are related to the syntaxin subfamily of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins involved in vesicular trafficking and exocytosis [3].
• RGS9.Gbeta5 is anchored to photoreceptor disc membranes by the transmembrane protein, R9AP [4].
• Absence of the RGS9.Gbeta5 GTPase-activating complex in photoreceptors of the R9AP knockout mouse [4].

Biological context of Rgs9bp

• Here we report the cloning of chicken R9AP from an inner ear cDNA library and the isolation of a murine R9AP cDNA from a retinal library [1].
• The expression of R9AP beyond photoreceptors led us to examine potential alternative roles for R9AP besides anchoring RGS9-1 and we found sequence homology and structural similarity of the protein with members of the SNARE protein family [1].
• Phosphorylation of RGS9-1 by PKC had little effect on its activity in solution but significantly decreased its affinity for its membrane anchor protein and GAP enhancer, RGS9-1 anchor protein (R9AP) [5].

Other interactions of Rgs9bp

• This effect was a consequence of the complete absence of any detectable RGS9 from the retinas of R9AP knockout mice [4].

Analytical, diagnostic and therapeutic context of Rgs9bp

• Interestingly, sequence analysis of R9AP reveals the presence of a conserved R-SNARE (for soluble N-ethylmaleimide-sensitive factor attachment protein receptor) motif and a predicted overall structural homology with SNARE proteins involved in vesicular trafficking and fusion [6].

References