VISITING SPEAKER:
  Maturase proteins in higher-plants mitochondria group-II introns splicing
  - Expression of mtDNA in plants is complex, particularly at post-transcriptional level
		
Wed, 14 Sep 2011 11:00 - G.33 Bayliss Building, UWA
		
Dr Oren Ostersetzer-Biran,Inst Plant Sciences, Agricultural Research Organization (ARO), Volcani Center, Israel
The expression of the mtDNA in plants is complex, particularly at the
post-transcriptional level; RNA processing events which contribute to
organellar genome expression include hundreds of RNA-editing events and
the splicing of numerous group-II-type introns which lie within many
protein-coding genes required in both respiration and organellar genome
expression mediated functions. The splicing of the mt group-II introns
is therefore essential for organellar function and is dependent upon
different proteincous cofactors. While in non-plant systems, the
splicing of group-II introns is mediated by proteins encoded within the
introns themselves which are known as Maturases, only a single Maturase
ORF (matR, encoded within the forth intron in nad1 gene) was retained in
the mtDNA in plants; yet, its putative role(s) in the splicing of nad1
or additional organellar introns are yet to be established. Clues to
other proteins are scarce, but these are likely to be encoded within the
nucleus as beside MatR there are no obvious candidates among the
remaining ORFs within the mtDNA. Intriguingly, in addition to matR,
higher plants nuclear genomes also harbor four Maturase-related genes
(nMat 1 to 4), which exist in the nucleus as self-standing ORFs out of
the context of their “evolutionary related group-II introns hosts".
These are all predicted to reside within the mitochondria and are
therefore expected to function in the splicing of organellar introns.
GFP-localization analyses indicated that the four nuc-Mats are localized
to mitochondria in Arabidopsis. Analyses of the phenotypes associated
with various Arabidopsis 'knock-out' mutants established the roles of
the four nMats in the splicing of a different subset of mitochondrial
introns.
		
For more information:
  Jennifer Gillett
  jgillett@cyllene.uwa.edu.au
  6488 4416

Starts       : Wed, 14 Sep 2011 11:00
Ends         : Wed, 14 Sep 2011 11:45
		
Last Updated : Tue, 23 Aug 2011 11:43