From a1e85f615a8de28f536ccf3b9929abdea13cd631 Mon Sep 17 00:00:00 2001 From: Benedikt Venn <venn@bio.uni-kl.de> Date: Thu, 14 Jul 2022 08:42:39 +0000 Subject: [PATCH] Update README.md --- README.md | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/README.md b/README.md index ea35241..aac6ff2 100644 --- a/README.md +++ b/README.md @@ -1,8 +1,28 @@ # LPA2 Complexome Profiling +## Project description + Wild type and lpa2 mutant Chlamydomonas reinhardtii were grown mixotrophically at 30 uE light intensity. Proteins were extracted and BN-PAGE lanes of three biological replicates each were cut into 36 slices and subsequently analysed in a mass spectrometer. <img src="https://git.nfdi4plants.org/venn/LPA2_ComplexomeProfiling_Chlamy/-/raw/main/assays/GelBasedProteomics/dataset/GelPicture.png" alt="GelPicture" width="60%"/> + +_Figure 1: Blue native PAGE of three wild type and three lpa2 mutant samples._ + <img src="https://git.nfdi4plants.org/venn/LPA2_ComplexomeProfiling_Chlamy/-/raw/main/runs/plots/LPA2_Cre02.g105650.png" alt="lpa2 signal" width="70%"/> +_Figure 2: Profile of LPA2 protein along the BN-PAGE. While the wild type shows high intensities in all replicates, no signal is detected for the lpa2 mutant._ + + +## Publication + +**Title:** Complexome profiling on the Chlamydomonas lpa2 mutant reveals insights into PSII biogenesis and new PSII associated proteins. + +**Authors:** Spaniol B, Lang J, Venn B, Schake L, Sommer F, Mustas M, Geimer S, Wollman FA, Choquet Y + +**Info:** J Exp Bot. 2022 Jan 5;73(1):245-262. doi: 10.1093/jxb/erab390 + + +### Abstract + +While the composition and function of the major thylakoid membrane complexes are well understood, comparatively little is known about their biogenesis. The goal of this work was to shed more light on the role of auxiliary factors in the biogenesis of photosystem II (PSII). Here we have identified the homolog of LOW PSII ACCUMULATION 2 (LPA2) in Chlamydomonas. A Chlamydomonas reinhardtii lpa2 mutant grew slower in low light, was hypersensitive to high light, and exhibited aberrant structures in thylakoid membrane stacks. Chlorophyll fluorescence (Fv/Fm) was reduced by 38%. Synthesis and stability of newly made PSII core subunits D1, D2, CP43, and CP47 were not impaired. However, complexome profiling revealed that in the mutant CP43 was reduced to ~23% and D1, D2, and CP47 to ~30% of wild type levels. Levels of PSI and the cytochrome b6f complex were unchanged, while levels of the ATP synthase were increased by ~29%. PSII supercomplexes, dimers, and monomers were reduced to ~7%, ~26%, and ~60% of wild type levels, while RC47 was increased ~6-fold and LHCII by ~27%. We propose that LPA2 catalyses a step during PSII assembly without which PSII monomers and further assemblies become unstable and prone to degradation. The LHCI antenna was more disconnected from PSI in the lpa2 mutant, presumably as an adaptive response to reduce excitation of PSI. From the co-migration profiles of 1734 membrane-associated proteins, we identified three novel putative PSII associated proteins with potential roles in regulating PSII complex dynamics, assembly, and chlorophyll breakdown. -- GitLab