Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Vis Neurosci. 2001 May-Jun;18(3):393-9.

Salamander UV cone pigment: sequence, expression, and spectral properties.

Author information

  • 1Department of Ophthalmology, Medical University of South Carolina, Charleston 29403, USA. majx@musc.edu

Abstract

The visual pigment from the ultraviolet (UV) cone photoreceptor of the tiger salamander has been cloned, expressed, and characterized. The cDNA contains a full-length open reading frame encoding 347 amino acids. The phylogenetic analysis indicates that the highest sequence homology is to the visual pigments in the S group. The UV opsin was tagged at the carboxy-terminus with the sequence for the 1D4 epitope. This fusion opsin was expressed in COS-1 cells, regenerated with 11-cis retinal (A1) and immuno-purified, yielding a pigment with an absorbance maximum (lambdamax) of 356 nm which is blue shifted from the absorption of retinal itself. The transducin activation assay demonstrated that this pigment is able to activate rod transducin in a light-dependent manner. Regeneration with 11-cis 3,4-dehydroretinal (A2) yielded a pigment with a lambdamax of 360 nm, only 4 nm red shifted from that of the A1 pigment, while bovine rhodopsin generated with A2 showed a 16-nm red shift from the corresponding A1 pigment. These results demonstrate that the trend for a shorter wavelength pigment to have a smaller shift of lambdamax between the A1 and A2 pigments also fits UV pigments. We hypothesize that the small red shift with A2 could be due to a twist in the chromophore that essentially isolates the ring double bond(s) from conjugation with the rest of the polyene chain.

PMID:
11497415
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Cambridge University Press
    Loading ...
    Write to the Help Desk