title: The SKP1-like gene family of Arabidopsis exhibits a high degree of differential gene expression and gene product interaction during development.
abstract: The Arabidopsis thaliana genome encodes several families of polypeptides that are known or predicted to participate in the formation of the SCF-class of E3-ubiquitin ligase complexes. One such gene family encodes the Skp1-like class of polypeptide subunits, where 21 genes have been identified and are known to be expressed in Arabidopsis. Phylogenetic analysis based on deduced polypeptide sequence organizes the family of ASK proteins into 7 clades. The complexity of the ASK gene family, together with the close structural similarity among its members raises the prospect of significant functional redundancy among select paralogs. We have assessed the potential for functional redundancy within the ASK gene family by analyzing an expanded set of criteria that define redundancy with higher resolution. The criteria used include quantitative expression of locus-specific transcripts using qRT-PCR, assessment of the sub-cellular localization of individual ASK:YFP auto-fluorescent fusion proteins expressed in vivo as well as the in planta assessment of individual ASK-F-Box protein interactions using bimolecular fluorescent complementation techniques in combination with confocal imagery in live cells. The results indicate significant functional divergence of steady state transcript abundance and protein-protein interaction specificity involving ASK proteins in a pattern that is poorly predicted by sequence-based phylogeny. The information emerging from this and related studies will prove important for defining the functional intersection of expression, localization and gene product interaction that better predicts the formation of discrete SCF complexes, as a prelude to investigating their molecular mode of action.
authors.affiliation: Department of Biological Sciences, University of Windsor, Windsor, Ontario, Canada.
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Dezfulian
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Soulliere
authors.forename: Rajdeep K
authors.initials: RK
authors.lastname: Dhaliwal
authors.forename: Madhulika
authors.initials: M
authors.lastname: Sareen
authors.forename: William L
authors.initials: WL
authors.lastname: Crosby
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D044783:F-Box Proteins / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D018613:Microscopy, Confocal; D005810:Multigene Family / Q000235:genetics*; D009928:Organ Specificity / Q000235:genetics; D010802:Phylogeny; D030821:Plants, Genetically Modified; D011485:Protein Binding / Q000235:genetics; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D044843:SKP Cullin F-Box Protein Ligases / Q000235:genetics*; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D044783:F-Box Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D044843:SKP Cullin F-Box Protein Ligases