Proteomic analysis of the pyrenoid‐traversing membranes of Chlamydomonas reinhardtii reveals novel components
Year: 2025
Type: article
Abstract: Summary Pyrenoids are algal CO 2 -fixing organelles that mediate approximately one-third of global carbon fixation. Most pyrenoids are traversed by membranes that are thought to supply them with concentrated CO 2 . Despite the critical nature of these membranes for pyrenoid function, they are poorly understood, with few protein components known in any species. Here, we identify protein components of the pyrenoid-traversing membranes from the leading model alga, Chlamydomonas reinhardtii, by affinity purification and mass spectrometry of membrane fragments. Our proteome includes previously-known proteins as well as novel candidates. We further characterize two of the novel pyrenoid-traversing membrane-resident proteins: Cre10.g452250, which we name Pyrenoid Membrane Enriched 1 (PME1), and Cre02.g143550, also known as Low-CO 2 -Induced 16 (LCI16). We confirm the pyrenoid-traversing membrane localization of LCI16 and observe that PME1 and LCI16 physically interact. We find that neither protein is required for normal membrane morphology or growth under CO 2 -limiting conditions, but that both mutants show a similar proteomic profile to those of established pyrenoid mutants. Taken together, our study identifies the proteome of the pyrenoid-traversing membranes and initiates the characterization of a novel pyrenoid-traversing membrane complex, building toward a mechanistic understanding of the pyrenoid.
Source: New Phytologist
DOI: 10.1111/nph.70669
Institutions: Princeton University, Howard Hughes Medical Institute
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $5,790
Funders: National Science Foundation, Howard Hughes Medical Institute, Bill and Melinda Gates Foundation, Princeton University, Princeton Center for Complex Materials, Foreign, Commonwealth and Development Office, National Institutes of Health, Materials Research Science and Engineering Center, Harvard University, National Institute of General Medical Sciences, Division of Materials Research, Division of Molecular and Cellular Biosciences
Awards: G1052925518, G1746067696, G2174132073, G2696751721, G3603580073, G5823110225, Collaborative Research: A community resource for genome-scale identification of genotype-phenotype relationships in a model photosynthetic eukaryote, G6536552022, Princeton Center for Complex Materials, Learning principles from the pyrenoid, a phase-separated organelle, G7674880502, Princeton University - To engineer a pyrenoid-based CO2 concentrating mechanism into land plants to improve crop performance in a changing climate., 22BBSRC-NSF/BIO: A synthetic pyrenoid to guide the engineering of enhanced crops, G8796015713, G9000078355
OpenAlex ID: W4415374443