SAG binds p-MII to form p-MII:SAG

Stable Identifier
R-HSA-2581488
Type
Reaction [binding]
Species
Homo sapiens
Compartment
cytosol, photoreceptor disc membrane
ReviewStatus
5/5
Locations in the PathwayBrowser
Expand all
General
SVG | 
PNG
Low
Medium
High
 | PPTX  | SBGN
SAG binds p-MII to form p-MII:SAG
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout
Although phosphorylation of activated rhodopsin (MII) reduces transducin activation, complete deactivation occurs only after arrestin (S-antigen or SAG, Yamaki et al. 1988) binds to and sterically caps MII. SAG is capable of binding unphosphorylated MII, but with very low probability. Binding affinity increases greatly upon phosphorylation. Binding of SAG generally occurs after MII has been phosphorylated ~3 times, and binding prevents further phosphorylation. Interestingly, rods express a small amount of a splice variant of SAG, P44, but its function is not yet known. Defects in SAG cause Oguchi type 1 disease (CSNBO1; MIM:258100), a recessive form of congenital stationary night blindness characterized by impaired scotopic vision (Fuchs et al. 1995).
Literature References
PubMed ID Title Journal Year
3164688 The sequence of human retinal S-antigen reveals similarities with alpha-transducin.

Shinohara, T, Tsuda, M, Yamaki, K

FEBS Lett 1988
7670478 A homozygous 1-base pair deletion in the arrestin gene is a frequent cause of Oguchi disease in Japanese

Gal, A, Nakazawa, M, Maw, M, Tamai, M, Fuchs, S, Oguchi, Y

Nat. Genet. 1995
Participants
Input
Output
Participates
as an event of
Inferred From
Sag binds p-MII to form p-MII:Sag (Bos taurus)
Authored
Jassal, B  (2012-11-13)
Reviewed
Makino, C  (2013-04-11)
Created
Jassal, B  (2012-11-13)
Cite Us!