Curvature thylakoid 1 proteins modulate prolamellar body morphology and promote organized thylakoid biogenesis in Arabidopsis thaliana

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt

The term “de-etiolation” refers to the light-dependent differentiation of etioplasts to chloroplasts in angiosperms. The underlying process involves reorganization of prolamellar bodies (PLBs) and prothylakoids into thylakoids, with concurrent changes in protein, lipid, and pigment composition, which together lead to the assembly of active photosynthetic complexes. Despite the highly conserved structure of PLBs among land plants, the processes that mediate PLB maintenance and their disassembly during de-etiolation are poorly understood. Among chloroplast thylakoid membrane-localized proteins, to date, only Curvature thylakoid 1 (CURT1) proteins were shown to exhibit intrinsic membrane-bending capacity. Here, we show that CURT1 proteins, which play a critical role in grana margin architecture and thylakoid plasticity, also participate in de-etiolation and modulate PLB geometry and density. Lack of CURT1 proteins severely perturbs PLB organization and vesicle fusion, leading to reduced accumulation of the light-dependent enzyme protochlorophyllide oxidoreductase (LPOR) and a delay in the onset of photosynthesis. In contrast, overexpression of CURT1A induces excessive bending of PLB membranes, which upon illumination show retarded disassembly and concomitant overaccumulation of LPOR, though without affecting greening or the establishment of photosynthesis. We conclude that CURT1 proteins contribute to the maintenance of the paracrystalline PLB morphology and are necessary for efficient and organized thylakoid membrane maturation during de-etiolation.

OriginalsprogEngelsk
Artikelnummere2113934118
TidsskriftProceedings of the National Academy of Sciences of the United States of America
Vol/bind118
Udgave nummer42
Antal sider10
ISSN0027-8424
DOI
StatusUdgivet - 2021

Bibliografisk note

Funding Information:
M.P. acknowledges funding from the Novo Nordisk Foundation (NNF15OC0016586), the Danish Council for Independent Research (7017-00122A), and the Copenhagen Plant Science Centre, University of Copenhagen. ?.K. acknowledges funding from the National Science Centre, Poland, under Grant No. 2019/35/D/NZ3/03904. R.B. acknowledges financial support from the Deutsche Forschungsgemeinschaft (FOR 2092; BO 1482/17-2). A.S. was the recipient of a postdoctoral fellowship from the Carlsberg Foundation. We thank the Center for Advanced Bioimaging at the University of Copenhagen for providing facilities for TEM sample preparation and microscopy and the Core Facility for Integrated Microscopy in the Panum Institute (University of Copenhagen) for assistance with immunogold labeling and microscopy.

Funding Information:
ACKNOWLEDGMENTS. M.P. acknowledges funding from the Novo Nordisk Foundation (NNF15OC0016586), the Danish Council for Independent Research (7017-00122A), and the Copenhagen Plant Science Centre, University of Copenhagen. Ł.K. acknowledges funding from the National Science Centre, Poland, under Grant No. 2019/35/D/NZ3/03904. R.B. acknowledges financial support from the Deutsche Forschungsgemeinschaft (FOR 2092; BO 1482/ 17-2). A.S. was the recipient of a postdoctoral fellowship from the Carlsberg Foundation. We thank the Center for Advanced Bioimaging at the University of Copenhagen for providing facilities for TEM sample preparation and microscopy and the Core Facility for Integrated Microscopy in the Panum Institute (University of Copenhagen) for assistance with immunogold labeling and microscopy.

Publisher Copyright:
© 2021 National Academy of Sciences. All rights reserved.

Links

ID: 282669374