[2015 Spring Life Sciences & IBB Regular Seminar]
  
    
 ▶Subject: Circadian Rhythms: from Genes to Behavior
        
 
 ▶Speaker: Prof. Seung-Hee Yoo (UT Health Science Center at Houston)
          

▶Date: 4:00PM/March/6(Fri)/2015
         
   
 ▶Place: Auditorium(1F), Postech Biotech Center
         
 
        *Abctract
       Combining N-ethyl-N-nitrosourea (ENU) based forward genetic screening with circadian behavior assays and positional cloning, we characterized two circadian mutants showing abnormal periods. First, using a long-period mouse mutant named Overtime (Ovtm), we cloned a hypomorphic point mutation (I364T) in the gene encoding the F-box containing E3 ligase Fbxl3. I demonstrated that FBXL3 plays a predominant role in determining the rate of CRY protein turnover, hence serving as a key regulatory E3 ligase for circadian periodicity. Fortuitously, subsequent cloning of a short-period circadian mutant, Past-time, revealed a G149E mutation in Fbxl21 encoding another E3 ligase paralogous to FBXL3. Biochemical studies uncovered a surprising dual function of this new E3 ligase. FBXL21 on the one hand forms an SCF (Skp, Cullin, F-box) E3 ligase complex that slowly degrades CRY in the cytoplasm, on the other hand also antagonizes the stronger E3 ligase activity of FBXL3 in the nucleus. These studies reveal an elegant post-translational regulatory mechanism of the core clock, highlighting the exquisite precision of the biological clockwork

 ▶Inquiry: Prof.Kyong Tai Kim(279-2297)
        
  
  * This seminar will be given in English