| Structural highlights
Function
MRL7L_ARATH Plays an essential role in early steps of chloroplast development (PubMed:21515910, PubMed:24111559). Involved in the regulation of plastid gene expression (PubMed:21515910, PubMed:24111559). Required for the proper function of the plastid transcriptional machinery and protein accumulation in thylakoid membranes. May function as molecular chaperone to ensure proper organization of the nucleoids in chloroplasts (PubMed:24111559).[1] [2]
Publication Abstract from PubMed
Phytochromes initiate chloroplast biogenesis by activating genes encoding the photosynthetic apparatus, including photosynthesis-associated plastid-encoded genes (PhAPGs). PhAPGs are transcribed by a bacterial-type RNA polymerase (PEP), but how phytochromes in the nucleus activate chloroplast gene expression remains enigmatic. We report here a forward genetic screen in Arabidopsis that identified NUCLEAR CONTROL OF PEP ACTIVITY (NCP) as a necessary component of phytochrome signaling for PhAPG activation. NCP is dual-targeted to plastids and the nucleus. While nuclear NCP mediates the degradation of two repressors of chloroplast biogenesis, PIF1 and PIF3, NCP in plastids promotes the assembly of the PEP complex for PhAPG transcription. NCP and its paralog RCB are non-catalytic thioredoxin-like proteins that diverged in seed plants to adopt nonredundant functions in phytochrome signaling. These results support a model in which phytochromes control PhAPG expression through light-dependent double nuclear and plastidial switches that are linked by evolutionarily conserved and dual-localized regulatory proteins.
NCP activates chloroplast transcription by controlling phytochrome-dependent dual nuclear and plastidial switches.,Yang EJ, Yoo CY, Liu J, Wang H, Cao J, Li FW, Pryer KM, Sun TP, Weigel D, Zhou P, Chen M Nat Commun. 2019 Jun 14;10(1):2630. doi: 10.1038/s41467-019-10517-1. PMID:31201314[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Qiao J, Ma C, Wimmelbacher M, Bornke F, Luo M. Two novel proteins, MRL7 and its paralog MRL7-L, have essential but functionally distinct roles in chloroplast development and are involved in plastid gene expression regulation in Arabidopsis. Plant Cell Physiol. 2011 Jun;52(6):1017-30. doi: 10.1093/pcp/pcr054. Epub 2011, Apr 22. PMID:21515910 doi:http://dx.doi.org/10.1093/pcp/pcr054
- ↑ Powikrowska M, Khrouchtchova A, Martens HJ, Zygadlo-Nielsen A, Melonek J, Schulz A, Krupinska K, Rodermel S, Jensen PE. SVR4 (suppressor of variegation 4) and SVR4-like: two proteins with a role in proper organization of the chloroplast genetic machinery. Physiol Plant. 2014 Mar;150(3):477-92. doi: 10.1111/ppl.12108. Epub 2013 Oct 16. PMID:24111559 doi:http://dx.doi.org/10.1111/ppl.12108
- ↑ Yang EJ, Yoo CY, Liu J, Wang H, Cao J, Li FW, Pryer KM, Sun TP, Weigel D, Zhou P, Chen M. NCP activates chloroplast transcription by controlling phytochrome-dependent dual nuclear and plastidial switches. Nat Commun. 2019 Jun 14;10(1):2630. doi: 10.1038/s41467-019-10517-1. PMID:31201314 doi:http://dx.doi.org/10.1038/s41467-019-10517-1
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