Spt-Ada-Gcn5-Acetyltransferase (SAGA) Complex in Plants: Genome Wide Identification, Evolutionary Conservation and Functional Determination.
The recruitment of RNA polymerase II on a promoter is assisted by the assembly of basal transcriptional machinery in eukaryotes. The Spt-Ada-Gcn5-Acetyltransferase (SAGA) complex plays an important role in transcription regulation in eukaryotes. However, even in the advent of genome sequencing of various plants, SAGA complex has been poorly defined for their components and roles in plant development and physiological functions. Computational analysis of Arabidopsis thaliana and Oryza sativa genomes for SAGA complex resulted in the identification of 17 to 18 potential candidates for SAGA subunits. We have further classified the SAGA complex based on the conserved domains. Phylogenetic analysis revealed that the SAGA complex proteins are evolutionary conserved between plants, yeast and mammals. Functional annotation showed that they participate not only in chromatin remodeling and gene regulation, but also in different biological processes, which could be indirect and possibly mediated via the regulation of gene expression. The in silico expression analysis of the SAGA components in Arabidopsis and O. sativa clearly indicates that its components have a distinct expression profile at different developmental stages. The co-expression analysis of the SAGA components suggests that many of these subunits co-express at different developmental stages, during hormonal interaction and in response to stress conditions. Quantitative real-time PCR analysis of SAGA component genes further confirmed their expression in different plant tissues and stresses. The expression of representative salt, heat and light inducible genes were affected in mutant lines of SAGA subunits in Arabidopsis. Altogether, the present study reveals expedient evidences of involvement of the SAGA complex in plant gene regulation and stress responses.
Plant Molecular Biology & Genetic Engineering Laboratory, Council of Scientific and Industrial Research, National Botanical Research Institute (CSIR-NBRI), Lucknow, Uttar Pradesh, India; School of Biotechnology, Faculty of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Rakesh
R
Srivastava
Plant Molecular Biology & Genetic Engineering Laboratory, Council of Scientific and Industrial Research, National Botanical Research Institute (CSIR-NBRI), Lucknow, Uttar Pradesh, India.
Krishan Mohan
KM
Rai
Plant Molecular Biology & Genetic Engineering Laboratory, Council of Scientific and Industrial Research, National Botanical Research Institute (CSIR-NBRI), Lucknow, Uttar Pradesh, India.
Bindu
B
Pandey
National Agri-Food Biotechnology Institute (DBT), Mohali, Panjab, India.
Sudhir P
SP
Singh
Plant Molecular Biology & Genetic Engineering Laboratory, Council of Scientific and Industrial Research, National Botanical Research Institute (CSIR-NBRI), Lucknow, Uttar Pradesh, India.
Samir V
SV
Sawant
D005075:Biological Evolution; D032461:Chromosomes, Plant; D016000:Cluster Analysis; D017124:Conserved Sequence; D030561:Databases, Nucleic Acid; D019143:Evolution, Molecular; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D018745:Genome, Plant; D055106:Genome-Wide Association Study; D058977:Molecular Sequence Annotation; D046912:Multiprotein Complexes / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000378:metabolism*; D010944:Plants / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D060066:Protein Interaction Maps; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics; D015534:Trans-Activators / Q000378:metabolism*
D046912:Multiprotein Complexes; D010940:Plant Proteins; D021122:Protein Subunits; D015534:Trans-Activators