| Structural highlights
5t0q is a 2 chain structure with sequence from Arath. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Related: | 5t0f, 4rqw, 4rru, 4rs9, 4ywc, 4yz6 |
| Gene: | MYC3, ATR2, BHLH5, EN36, At5g46760, MZA15.18 (ARATH), TIFY9, JAS1, JAZ10, At5g13220, T31B5.40 (ARATH) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[MYC3_ARATH] Transcription factor involved in tryptophan, jasmonic acid (JA) and other stress-responsive gene regulation. With MYC2 and MYC4, controls additively subsets of JA-dependent responses. Can form complexes with all known glucosinolate-related MYBs to regulate glucosinolate biosynthesis. Binds to the G-box (5'-CACGTG-3') of promoters. Activates multiple TIFY/JAZ promoters.[1] [2] [3] [4] [5] [TIF9_ARATH] Modulator of growth inhibition. Isoform 2 and isoform 3, but not isoform 1, confer a strong methyl-jasmonate insensitivity. Not involved in the growth response to salicylic acid or indole-3-acetic acid. Isoform 3 acts as an endogenous repressor of JA signal output in JA-stimulated cells (PubMed:19151223).[6] [7] [8]
Publication Abstract from PubMed
Jasmonate ZIM-domain (JAZ) transcriptional repressors play a key role in regulating jasmonate (JA) signaling in plants. Below a threshold concentration of jasmonoyl isoleucine (JA-Ile), the active form of JA, the C-terminal Jas motif of JAZ proteins binds MYC transcription factors to repress JA signaling. With increasing JA-Ile concentration, the Jas motif binds to JA-Ile and the COI1 subunit of the SCFCOI1 E3 ligase, which mediates ubiquitination and proteasomal degradation of JAZ repressors, resulting in derepression of MYC transcription factors. JA signaling subsequently becomes desensitized, in part by feedback induction of JAZ splice variants that lack the C-terminal Jas motif but include an N-terminal cryptic MYC-interaction domain (CMID). The CMID sequence is dissimilar to the Jas motif and is incapable of recruiting SCFCOI1, allowing CMID-containing JAZ splice variants to accumulate in the presence of JA and to re-repress MYC transcription factors as an integral part of reestablishing signal homeostasis. The mechanism by which the CMID represses MYC transcription factors remains elusive. Here we describe the crystal structure of the MYC3-CMIDJAZ10 complex. In contrast to the Jas motif, which forms a single continuous helix when bound to MYC3, the CMID adopts a loop-helix-loop-helix architecture with modular interactions with both the Jas-binding groove and the backside of the Jas-interaction domain of MYC3. This clamp-like interaction allows the CMID to bind MYC3 tightly and block access of MED25 (a subunit of the Mediator coactivator complex) to the MYC3 transcriptional activation domain, shedding light on the enigmatic mechanism by which JAZ splice variants desensitize JA signaling.
Structural insights into alternative splicing-mediated desensitization of jasmonate signaling.,Zhang F, Ke J, Zhang L, Chen R, Sugimoto K, Howe GA, Xu HE, Zhou M, He SY, Melcher K Proc Natl Acad Sci U S A. 2017 Feb 14;114(7):1720-1725. doi:, 10.1073/pnas.1616938114. Epub 2017 Jan 30. PMID:28137867[9]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Smolen GA, Pawlowski L, Wilensky SE, Bender J. Dominant alleles of the basic helix-loop-helix transcription factor ATR2 activate stress-responsive genes in Arabidopsis. Genetics. 2002 Jul;161(3):1235-46. PMID:12136026
- ↑ Cheng Z, Sun L, Qi T, Zhang B, Peng W, Liu Y, Xie D. The bHLH transcription factor MYC3 interacts with the Jasmonate ZIM-domain proteins to mediate jasmonate response in Arabidopsis. Mol Plant. 2011 Mar;4(2):279-88. doi: 10.1093/mp/ssq073. Epub 2011 Jan 17. PMID:21242320 doi:http://dx.doi.org/10.1093/mp/ssq073
- ↑ Niu Y, Figueroa P, Browse J. Characterization of JAZ-interacting bHLH transcription factors that regulate jasmonate responses in Arabidopsis. J Exp Bot. 2011 Mar;62(6):2143-54. doi: 10.1093/jxb/erq408. Epub 2011 Feb 14. PMID:21321051 doi:http://dx.doi.org/10.1093/jxb/erq408
- ↑ Fernandez-Calvo P, Chini A, Fernandez-Barbero G, Chico JM, Gimenez-Ibanez S, Geerinck J, Eeckhout D, Schweizer F, Godoy M, Franco-Zorrilla JM, Pauwels L, Witters E, Puga MI, Paz-Ares J, Goossens A, Reymond P, De Jaeger G, Solano R. The Arabidopsis bHLH transcription factors MYC3 and MYC4 are targets of JAZ repressors and act additively with MYC2 in the activation of jasmonate responses. Plant Cell. 2011 Feb;23(2):701-15. doi: 10.1105/tpc.110.080788. Epub 2011 Feb 18. PMID:21335373 doi:http://dx.doi.org/10.1105/tpc.110.080788
- ↑ Schweizer F, Fernandez-Calvo P, Zander M, Diez-Diaz M, Fonseca S, Glauser G, Lewsey MG, Ecker JR, Solano R, Reymond P. Arabidopsis basic helix-loop-helix transcription factors MYC2, MYC3, and MYC4 regulate glucosinolate biosynthesis, insect performance, and feeding behavior. Plant Cell. 2013 Aug;25(8):3117-32. doi: 10.1105/tpc.113.115139. Epub 2013 Aug, 13. PMID:23943862 doi:http://dx.doi.org/10.1105/tpc.113.115139
- ↑ Yan Y, Stolz S, Chetelat A, Reymond P, Pagni M, Dubugnon L, Farmer EE. A downstream mediator in the growth repression limb of the jasmonate pathway. Plant Cell. 2007 Aug;19(8):2470-83. Epub 2007 Aug 3. PMID:17675405 doi:http://dx.doi.org/10.1105/tpc.107.050708
- ↑ Chung HS, Howe GA. A critical role for the TIFY motif in repression of jasmonate signaling by a stabilized splice variant of the JASMONATE ZIM-domain protein JAZ10 in Arabidopsis. Plant Cell. 2009 Jan;21(1):131-45. doi: 10.1105/tpc.108.064097. Epub 2009 Jan 16. PMID:19151223 doi:http://dx.doi.org/10.1105/tpc.108.064097
- ↑ Moreno JE, Shyu C, Campos ML, Patel LC, Chung HS, Yao J, He SY, Howe GA. Negative feedback control of jasmonate signaling by an alternative splice variant of JAZ10. Plant Physiol. 2013 Jun;162(2):1006-17. doi: 10.1104/pp.113.218164. Epub 2013 Apr, 30. PMID:23632853 doi:http://dx.doi.org/10.1104/pp.113.218164
- ↑ Zhang F, Ke J, Zhang L, Chen R, Sugimoto K, Howe GA, Xu HE, Zhou M, He SY, Melcher K. Structural insights into alternative splicing-mediated desensitization of jasmonate signaling. Proc Natl Acad Sci U S A. 2017 Feb 14;114(7):1720-1725. doi:, 10.1073/pnas.1616938114. Epub 2017 Jan 30. PMID:28137867 doi:http://dx.doi.org/10.1073/pnas.1616938114
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