Speaker: Michael Z. Lin, M.D. Ph.D., Stanford University
Assistant Professor, Depts. of Pediatrics and Bioengineering
Fluorescent proteins: New forms and unexpected new functions
Abstract:
Classical beta-barrel fluorescent proteins (FPs) are widely used as sensors of protein localization and activity, while other classes of light-absorbing proteins have been proposed for whole-body imaging in mammals and for optogenetic control of proteins with light. We will report on recent successes in engineering new forms of classical FPs that establish their utility for these applications as well. First, we performed structure-guided mutagenesis to engineer bright far-red FPs that provide substantially better brightness and signal over background in deep-tissue imaging compared to phytochrome-based proteins, enabling longitudinal visualization of stem cell differentiation in mice. Second, we discovered a previously unknown feature of variants of the photochromic green FP Dronpa, the ability to undergo light-dependent dissociation and association. To our knowledge, this is the first case of a domain acquiring light-responsive interaction ability via engineering in the laboratory. We further used this feature to create light-controllable proteins of a simple modular design that is generalizable and has self-reporting abilities, features that have yet to be achieved by other photoactive protein domains. Our findings extend the applications of FPs to new imaging modalities as well as beyond imaging to optogenetic control.
Speaker: Michael Z. Lin
Venue: New Biology Building 407（新馆407）
Time: June 4 (Tuesday), 2013; 16:30 pm
Host: Prof. Ting Zhu
