Mechanisms of Gene Regulation
Annamalai, Devi , Schuler, Mary A. .
Relation between Development and Splicing :Functional analysis of Arabidopsis thaliana PRP18 family, SLU7-2 family and PRP16 proteins potentially involved in second step of splicing 1Devi Annamalai1 and 2.
Plant pre-mRNA splicing displays some unique features in comparison with yeast and mammalian systems due to variations in intron sequences and possible multiple functions of its splicing factors. PRP18 (Pre mRNA Protein) is a constitutively expressed general splicing factor first identified in yeast. It has been shown to interact with the SLU7 protein, one of the other crucial second step splicing factor also shown to be constitutively expressed. In yeast and other higher eukaryotes it has been shown that PRP18 and SLU7 interacts with U5 snRNP together during second step of splicing process. Constitutively expressed PRP16 protein is a RNA helicase and has a role in rearrangement of the spliceosomes during second step of splicing in yeast and other higher eukaryotes. Unlike in yeast and mammals, Arabidopsis thaliana (At) has a small subfamily of PRP18 (AtPRP18a and AtPRP18b) and SLU7-2 (AtSLU7-2, AtSLU7-1A, AtSLU7-1B) related proteins. AtPRP18a and AtPRP18b share 72% amino acid identity with each other. AtSLU7-A and AtSLU7-1B shares 89% identity with each other and with SLU7-2 they share 74% and 75% respectively. To their corresponding yeast and human homolog, AtPRP18a shares 28% and 35% identity and AtPRP18b shares 23% and 40% identity. And SLU7 family shares 21-22% and 39-46% identity with its yeast and human homologes respectively. Similarly, AtPRP16 shares about 59% and 41% with human and yeast homologs respectively. RT-PCR analyses have demonstrated that the AtPRP18 family, AtSLU7 family and AtPRP16 are differentially expressed in spatial and temporal manner. AtPRP18a T-DNA knockout line carrying an insertion in the 3’UTR is being analyzed to determine their potential roles in plant development. Genomic PCR analyses have shown that these T-DNA knockout lines propagate only in their hemizygous state thus indicating lethality of homozygous knockouts. RT-PCR analysis indicate downregulation of AtPRP18a expression in hemizygous knockout plants. At the same time, Phenotypic and molecular analysis indicates that these hemizygous lines are compromised in their overall development. Studies are underway to identify other possible targets and regulation of these splicing factors.
Log in to add this item to your schedule
1 - University if illinois Urbana-Champaign, Plant biology, 1201. W.Gregory Dr., 161 ERML, Urbana, IL, 61801, USA
2 - University if illinois Urbana-Champaign, Cell and Development biology
second step splcing factors in arabidopsis
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM