5ewu

Structural highlights

Function

[CHLH_ARATH] Multifunctional protein involved in chlorophyll synthesis, plastid-to-nucleus retrograde signaling and abscisic acid (ABA) perception. In chlorophyll synthesis, catalyzes the insertion of magnesium ion into protoporphyrin IX to yield Mg-protoporphyrin IX. The reaction takes place in two steps, with an ATP-dependent activation followed by an ATP-dependent chelation step. In addition to its function in the Mg-chelatase enzyme, is required for the plastid-to-nucleus retrograde signaling. The plastid-to-nucleus signal plays an important role in the coordinated expression of both nuclear- and chloroplast-localized genes that encode photosynthesis-related proteins. Has a role in mediating ABA signaling in stomatal guard cells and during seed germination. Binds ABA and is a positive regulator of ABA signaling.^{[1] [2] [3] [4] [5] [6] [7]}

References

1. ↑ Mochizuki N, Brusslan JA, Larkin R, Nagatani A, Chory J. Arabidopsis genomes uncoupled 5 (GUN5) mutant reveals the involvement of Mg-chelatase H subunit in plastid-to-nucleus signal transduction. Proc Natl Acad Sci U S A. 2001 Feb 13;98(4):2053-8. PMID:11172074 doi:http://dx.doi.org/10.1073/pnas.98.4.2053
2. ↑ Shen YY, Wang XF, Wu FQ, Du SY, Cao Z, Shang Y, Wang XL, Peng CC, Yu XC, Zhu SY, Fan RC, Xu YH, Zhang DP. The Mg-chelatase H subunit is an abscisic acid receptor. Nature. 2006 Oct 19;443(7113):823-6. PMID:17051210 doi:http://dx.doi.org/10.1038/nature05176
3. ↑ Huang YS, Li HM. Arabidopsis CHLI2 can substitute for CHLI1. Plant Physiol. 2009 Jun;150(2):636-45. doi: 10.1104/pp.109.135368. Epub 2009 Apr , 10. PMID:19363094 doi:http://dx.doi.org/10.1104/pp.109.135368
4. ↑ Wu FQ, Xin Q, Cao Z, Liu ZQ, Du SY, Mei C, Zhao CX, Wang XF, Shang Y, Jiang T, Zhang XF, Yan L, Zhao R, Cui ZN, Liu R, Sun HL, Yang XL, Su Z, Zhang DP. The magnesium-chelatase H subunit binds abscisic acid and functions in abscisic acid signaling: new evidence in Arabidopsis. Plant Physiol. 2009 Aug;150(4):1940-54. doi: 10.1104/pp.109.140731. Epub 2009 Jun, 17. PMID:19535472 doi:http://dx.doi.org/10.1104/pp.109.140731
5. ↑ Shang Y, Yan L, Liu ZQ, Cao Z, Mei C, Xin Q, Wu FQ, Wang XF, Du SY, Jiang T, Zhang XF, Zhao R, Sun HL, Liu R, Yu YT, Zhang DP. The Mg-chelatase H subunit of Arabidopsis antagonizes a group of WRKY transcription repressors to relieve ABA-responsive genes of inhibition. Plant Cell. 2010 Jun;22(6):1909-35. doi: 10.1105/tpc.110.073874. Epub 2010 Jun, 11. PMID:20543028 doi:http://dx.doi.org/10.1105/tpc.110.073874
6. ↑ Tsuzuki T, Takahashi K, Inoue S, Okigaki Y, Tomiyama M, Hossain MA, Shimazaki K, Murata Y, Kinoshita T. Mg-chelatase H subunit affects ABA signaling in stomatal guard cells, but is not an ABA receptor in Arabidopsis thaliana. J Plant Res. 2011 Jul;124(4):527-38. doi: 10.1007/s10265-011-0426-x. Epub 2011, May 12. PMID:21562844 doi:http://dx.doi.org/10.1007/s10265-011-0426-x
7. ↑ Du SY, Zhang XF, Lu Z, Xin Q, Wu Z, Jiang T, Lu Y, Wang XF, Zhang DP. Roles of the different components of magnesium chelatase in abscisic acid signal transduction. Plant Mol Biol. 2012 Nov;80(4-5):519-37. doi: 10.1007/s11103-012-9965-3. Epub, 2012 Sep 27. PMID:23011401 doi:http://dx.doi.org/10.1007/s11103-012-9965-3