Talk:Channelrhodopsin

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I think that the "History" section of this article has to be moved down, after "Structure" and "Function", because it is too long and detailed for a reader who is only interested in the basic info about these proteins, rather than in the priority struggle between channelrhodopsin researchers. Also, this section doesn't give any credit to scientists who contributed to research on channelrhodopsin function in algal cells before their sequences were identified at the molecular level. I am going to expand in this direction in the near future and hope that the previous contributors will agree that this is necessary to do, otherwise the reader gets an impression that channelrhodopsins emerged from nowhere.

Also, I think that a wider context should be provided when describing the structure, as animal visual rhodopsins are NOT the closest relatives of ChRs.Egovoru (talk) 23:51, 2 January 2012 (UTC)

this is a cool new topic... any thoughts?

Wow, the article is rapidly improving! This is not a stub any more. To do: 1)It is not clear what distinguishes the 'Further reading' articles from the other references. They are not reviews, but primary research papers. Cite them in the main text? 2) The 'Applications' section could get some substructure, e.g. slice work, in vivo, medical perspectives. 3) Picture of a ChR2 expressing nerve cell, anybody? —Preceding unsigned comment added by 84.73.127.87 (talk) 18:31, 15 September 2008 (UTC)

Shouldn't there be a mention of Ed Boyden somewhere on this page? See

Boyden, E. S., Zhang, F., Bamberg, E., Nagel, G., and Deisseroth, K. (2005) Millisecond-timescale, genetically-targeted optical control of neural activity. Nature Neuroscience 8(9):1263-1268.

or visit [Ed Boyden's page] for more information.

140.180.0.76 (talk) 20:58, 29 October 2008 (UTC)

Contradictions

Moved the following contradictory info here from main article:

"The peak absorbance of the ChR2 retinal complex is about 470 nm (blue). Peak absorbance of the ChR2 retinal complex is about 460 nm (blue). Together with the yellow light-activated chloride pump halorhodopsin, which inhibits neurons, ChR2 enables multiple-color optical activation and silencing of neural activity."

Fuzzform (talk) 21:10, 2 November 2008 (UTC)

"When the all-trans-retinal complex absorbs light, it induces a conformational change from all-trans to 13-cis-retinal. This conformational change introduces a further conformational change in the transmembrane protein opening the pore, to at least 6A."

No explanation for the phrase "...to at least 6A." Removed for the time being, pending explanation. Fuzzform (talk) 21:12, 2 November 2008 (UTC)

"The 13-cis-retinal naturally relaxes with time back to the all-trans-retinal..."

This is not necessarily true. Although it isn't explained in Purves, I suspect there is a recycling enzyme involved. Molecules don't switch from trans to cis (or vice versa) for no reason. Fuzzform (talk) 21:16, 2 November 2008 (UTC)

Fuzzform, this is another interesting suspicion of yours which happens to be true for vertebrate rhodopsin, but not for ChR. Would you please stop to use your textbook about the vertebrate nervous system to take guesses how bacterial rhodopsins work? This is Wikipedia! --Millencolin (talk) 21:37, 3 November 2008 (UTC)

"The 7-transmembrane nature of Channelrhodopsin-2 is fairly rare to ion channels which usually consist of similar repeating parts."

There's some confusion here. In this context, "7-transmembrane protein" is simply a synonym for "G-protein coupled receptor" (GPCR). What is rare is that ChR2 is a 7-transmembrane protein that isn't a GPCR. Also, the prase "...usually consist of similar repeating parts" is almost meaningless. Many proteins consist of repeating parts, especially transmembrane proteins. Fuzzform (talk) 21:25, 2 November 2008 (UTC)

"The C-terminal end of ChR2 extends well into the intracelluar space, whereas the N-terminal end consists of the 7-transmembrane section"

Lots of problems here. First of all, the N-terminal end extends in the intracellular space, and the C-terminal end into extracellular space. Secondly, the transmembrane domain is between the two termini, and the n-terminus does not "consist of the 7-transmembrane domain".Fuzzform (talk) 21:31, 2 November 2008 (UTC)

While the C-terminus of vertebrate rhodopsin is extracellular, this is not true for Channelrhodopsins (Nagel et al. PNAS 2003). Purves is not the only source of information on the planet. --Millencolin (talk) 18:33, 3 November 2008 (UTC)

Naming conventions

There is no Channelrhodopsin-3, although it might seem logical. The third Channelrhodopsin discovered (Zhang et al. 2008) has been termed VChR1. —Preceding unsigned comment added by Millencolin (talk • contribs) 16:11, 3 November 2008 (UTC)