Oral Presentation International Plant Molecular Biology Conference 2024

Thylakostasis and membrane remodeling molecules in photosynthetic organisms (#449)

Wataru Sakamoto 1 , Di Li 1 , Sarah Gachie 1 , Rentang Fajar Cakra Wibawa 1
  1. Okayama University, Kurashiki, OKAYAMA, Japan

Membrane remodeling is a crucial cellular process that is involved in endocytosis, exocytosis, fission, abscission, and membrane repair. Chloroplasts, which are vulnerable to light stress due to the photosynthetic reactions taking place within the organelle, are no exception to the requirement for membrane remodeling of both the envelope and thylakoid membranes; yet, little is understood regarding the molecules involved. VIPP1, originally identified in 1990’s as the protein colocalized to chloroplast inner envelope and thylakoid membrane, has been suggested to play a pivotal role in this process. Loss of VIPP1 in Arabidopsis results in a seedling lethal phenotype, indicating its essential function. VIPP1 forms a large (>2 MDa) homo-oligomers, which were shown to exhibit dynamic disassembly responding to hypotonic stress. Recently, the ring structure of cyanobacterial VIPP1 oligomers has been resolved, which supports previous findings in its lipid binding orchestrated by the N-terminal 7-helix of VIPP1, and its purine nucleotide hydrolysis activity. Interestingly, VIPP1 shows structural similarity to the ESCRT-III protein family involved in various kinds of membrane remodeling in the cytosol of yeast and humans. here, we summarize the context of thylakoid homeostasis (thylakostasis) during chloroplast development, with the main focus on VIPP1 protein.

  1. Gupta et al. (2021) Cell, 184: 3643-3659. Liu et al. (2021) Cell, 184: 3660-3673. Ohnishi et al. (2022) Frontiers Plant Sci., 13: 949578. Zhang et al. (2016) Plant Phys., 171: 1983-1995.