The Thylakoid Protein NTA1 Is An Assembly Factor of Cytochrome b6f Complex Essential for Chloroplast Development in Arabidopsis

ABSTRACT: The cytochrome b6f (Cyt b6f) complex is a multisubunit protein complex in chloroplast thylakoid membranes required for photosynthetic electron transport. Here we report the isolation and characterization of the new tiny albino (nta1) mutant in Arabidopsis, which had severe defects in Cyt b6f accumulation and chloroplast development. Gene cloning unveiled that the nta1 phenotypes were caused by the disruption of a single nuclear gene, NTA1, which encodes an integral thylakoid membrane protein conserved across green algae and plants. Overexpression of NTA1 completely rescued the nta1 phenotypes, while knockout of NTA1 in wild type plants recapitulated the mutant phenotypes. Loss of NTA1 function severely impaired the accumulation of multiprotein complexes related to photosynthesis in thylakoid membranes, particularly the components of Cyt b6f. Furthermore, NTA1 was shown to directly interact with four subunits (Cyt b6/PetB, PetD, PetG and PetN) of Cyt b6f through the DUF1279 domain and C-terminal sequence to mediate their assembly. Taken together, our study identified NTA1 as a new and key regulator of chloroplast development, which plays essential roles in the assembly of Cyt b6f complex through interacting with multiple Cyt b6f subunits.

INSTRUMENT(S): TripleTOF 5600

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Whole Body

SUBMITTER: Lei Feng  

LAB HEAD: Lei Feng

PROVIDER: PXD038714 | Pride | 2023-02-22

REPOSITORIES: Pride