Phosphodiesterase 6H, cone-specific inhibitor
PDE6H is an 83-amino-acid regulatory protein that binds to and inhibits the catalytic activity of the cone photoreceptor-specific cGMP phosphodiesterase (cone PDE6). Cone PDE6 comprises a catalytic homodimer of PDE6C to which PDE6H (cone γ-subunit) binds. Following stimulation of cone photoreceptor cells by light, the cone visual pigment activates a cone-specific heterotrimeric G-protein (cone transducin), which then activates cone PDE6 by binding to the PDE6H inhibitory subunit and relieving its inhibition at the cone PDE6C active site. This phototransduction pathway exists in the outer segment portion of the photoreceptor cell, an organelle highly specialized for light detection and visual signal transduction. Although much is known about the structure, function and regulation of the rod PDE6 by its inhibitory γ-subunit (PDE6G), the PDE6H subunit is much less studied to date. PDE6H is highly expressed in cone photoreceptor cells, although there are reports of non-retinal expression of PDE6H (but not of PDE6C) in other tissues.
Alternative names for this molecule: Cone phosphodiesterase 6 gamma; Cone-like cGMP-phosphodiesterase 6 gamma subunit type 2; GMP-PDE gamma; PDE6G (cone); PDE6H; Pde6h; PDEgamma; Phosphodiesterase 6H, cGMP-specific, cone, gamma; Phosphodiesterase 6H, cone-specific inhibitor; RCD3; Retinal cone rhodopsin-sensitive cGMP 3'',5''-cyclic phosphodiesterase subunit gamma; Retinal cone rhodopsin-sensitive cGMP 3',5'-cyclic phosphodiesterase subunit gamma This molecule exists in 8 states and has 9 transitions between these states.
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Digital Object Identifier (DOI)
Zhang, X. J. and Cote, R. H. Pde6H, cone-specific inhibitory subunit of cone PDE6. (2011) UCSD-Nature Molecule Pages doi:10.1038/mp.a001758.01.