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DTSTAMP:20260424T125156Z
UID:5a0bfaa77d6eb983556849@ist.ac.at
DTSTART:20171124T110000
DTEND:20171124T120000
DESCRIPTION:Speaker: Elliot Gerrard\nhosted by Harald Janovjak\nAbstract: V
 ision in animals depends on light-sensitive GPCRs\, rhodopsins\, which can
  also be employed for optogenetic control of g-protein signaling. We utili
 se a visible light sensitive opsin from the box jellyfish c.rastonii\, Jel
 lyOp\, for bleach-resistant control of the Gαs signaling cascade in human
  cells1. We find that JellyOp provides multiple advantages over currently 
 used chimeric tools in vitro\, including better light sensitivity\, more p
 otent and specific activation of the Gαs pathway and an absence of dark a
 ctivity2. We have also used JellyOp to perform the first structural invest
 igation of a radiate animal opsin. Lens eyes similar to those found in ver
 tebrates have separately evolved in box jellyfish\, but little is known ab
 out the structure of opsins found in these animals. Using homology modelin
 g and live cell experiments\, we find that a critical component of rhodops
 in tertiary structure\, the counterion\, has displaced in a similar manner
  during the separate evolution of vertebrate and box jellyfish opsins3. Je
 llyOps new counterion position is only the 3rd demonstrated in animal opsi
 n structures. This type of displacement is known to convey functional adva
 ntages to opsin function and is coincident with the appearance of lens eye
 s in both phyla. This structural investigation demonstrates an instance of
  convergent evolution and is now being used to further JellyOps applicatio
 n to optogenetics through the development of spectral tuning mutations. 1
 .Bailes\, H. J.\, Zhuang\, L.-Y. & Lucas\, R. J. Reproducible and Sustaine
 d Regulation of Gαs Signalling Using a Metazoan Opsin as an Optogenetic T
 ool. PLoS ONE 7\, e30774 (2012).2.Bailes\, H. J. et al. Optogenetic interr
 ogation reveals separable G-protein-dependent and -independent signalling 
 linking G-protein-coupled receptors to the circadian oscillator. BMC Biol.
  15\, 40 (2017).3. Gerrard\, E.G & Mutt\, E. et al\, Convergent evolution 
 of tertiary structure in visual proteins from lens eyes (Submitted\, Autum
 n 2017).
LOCATION:Seminar Room\, Lab Building East\, ISTA
ORGANIZER:amally@ist.ac.at
SUMMARY:Elliot Gerrard: Optogenetic applications and molecular evolution of
  JellyOp\, a box jellyfish opsin
URL:https://talks-calendar.ista.ac.at/events/959
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