BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Characterisation of Arabidopsis and Rice Homologues of Purine Nucl
 eoside Phosphorylases - Farhat Nazir
DTSTART:20140626T150000Z
DTEND:20140626T152500Z
UID:TALK51419@talks.cam.ac.uk
CONTACT:Megan Cooper
DESCRIPTION:Purine nucleoside phosphorylases (PNP) are thought to be invol
 ved in purine metabolism and rarely reported in plants. Bark storage prote
 in (BSP) and wound inducible (Win4) are poplar proteins with the consensus
  motifs for PNP activity\, which is unreported. Our group characterised a 
 distinct homologue\, StCKP1\, in potato\, an active PNP preferring cytokin
 ins as substrate that prolongs dormancy in tubers and seed dormancy in ara
 bidopsis. Arabidopsis has one homologue of StCKP1 and two of BSP/Win4\; ri
 ce has two versions of StCKP1 and one of BSP/Win4. \nI have expressed the 
 arabidopsis homologues of BSP/Win4 in E.coli using the pMal system\, and p
 urified the fusion proteins. PNP activity in both the phosphorolytic and s
 ynthetic directions was detected using an hplc-based assay. Both proteins 
 showed activity with adenine/ adenosine\, and one of the homologues is als
 o capable of interconverting a subset of cytokinins. Bacterially expressed
  protein of one of the rice homologues of STCKP1 interconverted cytokinins
 . The coding sequence for this homologue has been constitutively over-expr
 essed in wheat and T0 seed will shortly be available for dormancy determin
 ation.\nCurrent work includes determining kinetic constants for expressed 
 proteins\, and Southern analysis of T0 lines of wheat.\n
LOCATION:Department of Plant Sciences\, Large Lecture Theatre
END:VEVENT
END:VCALENDAR