WRKY
From RiceWiki
Brief Introduction
- The plant WRKY gene family was first identified from sweet potato by Ishiguro and Nakamura in the year 1994[1][2][3]. WRKY gene family members contain one or two highly conserved WRKY domains consisted of approximately 60 amino acids.In this WRKY domain,a conserved WRKYGQK sequence is followed by a C2H2- or C2HC-type of zinc finger motif in the C-terminal region.[2][3][4][5][6][7]. They can be classified on the basis of both the number of WRKY domains and the features of their zinc-finger-like motif. WRKY proteins with two WRKY domains are classified into Group I, whereas most proteins with one WRKY domain are classified into Group II. Generally, the WRKY domains of group I and group II members have the same type of finger motif, whose pattern of potential zinc ligands (C–X4–5–C–X22–23–H–X1–H) is unique among all described zinc-finger-like motifs. The single finger motif of a small subset of WRKY proteins is distinct from that of group I and II members. Instead of a C2–H2 pattern, their WRKY domains contain a C2–HC motif (C–X7–C–X23–H–X1–C). Owing to this distinction, they are assigned to the group III. The single WRKY domains of group II and III family members are more similar in sequence to the C-terminal than to the N-terminal WRKY domain of group I proteins, suggesting that the C-terminal and single WRKY domains are functionally equivalent and constitute the major DNA-binding domain. The conservation of the WRKY domain is mirrored by a remarkable conservation of the cognate cis-acting W box elements. These (T)(T)TGAC(C/T) sequence elements contain the invariant TGAC core, which is essential for function and WRKY binding.[2][5][6].
Figure 1. Protein Structure of Os01g082640 ( member of Group I ) 
Figure 2. Protein Structure of BGIOSGA003851 ( member of Group II ) - WRKY factors play a important role in responses to abiotic stresses and regulating the pathogen-induced defense program. Some WRKY factors are involved in responses to abiotic stresses and ABA. Some WRKY factors have been reported to be associated with defence-induced mitogen-activated protein kinase (MAPK) signaling cascades as well as disease resistance and responses to salicylic acid. Some WRKY proteins seem to be involved in some other plant-specific processes, such as trichome development, the biosynthesis of secondary metabolites and senescence[2][3][4][5].
- The previous phylogenetic analysis of WRKY domains showed WRKY domains of the same type forming independent domains within their species, suggesting that numerous WRKY gene duplications occurred after the divergence of the monocotyledons from dicotyledons some 50–80 million years ago[5][7].
- Pfam: PF03106
Japonica Group
Indica Group
References
- ↑
Ishiguro S, Nakamura K. Characterization of a cDNA encoding a novel DNA-binding protein, SPF1, that recognizes SP8 sequences in the 5' upstream regions of genes coding for sporamin and beta-amylase from sweet potato. Mol Gen Genet. 1994 Sep 28;244(6):563-71.
- ↑ 2.0 2.1 2.2 2.3
Eulgem T, Rushton P J, Robatzek S, et al. The WRKY superfamily of plant transcription factors[J]. Trends in plant science, 2000, 5(5): 199-206.
- ↑ 3.0 3.1 3.2
Ülker B, Somssich I E. WRKY transcription factors: from DNA binding towards biological function[J]. Current opinion in plant biology, 2004, 7(5): 491-498.
- ↑ 4.0 4.1
Ross C A, Liu Y, Shen Q J. The WRKY gene family in rice (Oryza sativa)[J]. Journal of Integrative Plant Biology, 2007, 49(6): 827-842.
- ↑ 5.0 5.1 5.2 5.3
Ramamoorthy R, Jiang S Y, Kumar N, et al. A comprehensive transcriptional profiling of the WRKY gene family in rice under various abiotic and phytohormone treatments[J]. Plant and cell physiology, 2008, 49(6): 865-879.
- ↑ 6.0 6.1
Xie Z, Zhang Z L, Zou X, et al. Annotations and functional analyses of the rice WRKY gene superfamily reveal positive and negative regulators of abscisic acid signaling in aleurone cells[J]. Plant physiology, 2005, 137(1): 176-189.
- ↑ 7.0 7.1
Wu K L, Guo Z J, Wang H H, et al. The WRKY family of transcription factors in rice and Arabidopsis and their origins[J]. DNA research, 2005, 12(1): 9-26.
