TY - JOUR
T1 - A Spatial Interactome Reveals the Protein Organization of the Algal CO2-Concentrating Mechanism
AU - Mackinder, Luke C.M.
AU - Chen, Chris
AU - Leib, Ryan D.
AU - Patena, Weronika
AU - Blum, Sean R.
AU - Rodman, Matthew
AU - Ramundo, Silvia
AU - Adams, Christopher M.
AU - Jonikas, Martin C.
N1 - Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2017/9/21
Y1 - 2017/9/21
N2 - Approximately one-third of global CO2 fixation is performed by eukaryotic algae. Nearly all algae enhance their carbon assimilation by operating a CO2-concentrating mechanism (CCM) built around an organelle called the pyrenoid, whose protein composition is largely unknown. Here, we developed tools in the model alga Chlamydomonas reinhardtii to determine the localizations of 135 candidate CCM proteins and physical interactors of 38 of these proteins. Our data reveal the identity of 89 pyrenoid proteins, including Rubisco-interacting proteins, photosystem I assembly factor candidates, and inorganic carbon flux components. We identify three previously undescribed protein layers of the pyrenoid: a plate-like layer, a mesh layer, and a punctate layer. We find that the carbonic anhydrase CAH6 is in the flagella, not in the stroma that surrounds the pyrenoid as in current models. These results provide an overview of proteins operating in the eukaryotic algal CCM, a key process that drives global carbon fixation.
AB - Approximately one-third of global CO2 fixation is performed by eukaryotic algae. Nearly all algae enhance their carbon assimilation by operating a CO2-concentrating mechanism (CCM) built around an organelle called the pyrenoid, whose protein composition is largely unknown. Here, we developed tools in the model alga Chlamydomonas reinhardtii to determine the localizations of 135 candidate CCM proteins and physical interactors of 38 of these proteins. Our data reveal the identity of 89 pyrenoid proteins, including Rubisco-interacting proteins, photosystem I assembly factor candidates, and inorganic carbon flux components. We identify three previously undescribed protein layers of the pyrenoid: a plate-like layer, a mesh layer, and a punctate layer. We find that the carbonic anhydrase CAH6 is in the flagella, not in the stroma that surrounds the pyrenoid as in current models. These results provide an overview of proteins operating in the eukaryotic algal CCM, a key process that drives global carbon fixation.
KW - CCM
KW - CO-concentrating mechanism
KW - Chlamydomonas reinhardtii
KW - Rubisco
KW - affinity purification mass spectrometry
KW - carbon fixation
KW - high-throughput fluorescence protein tagging
KW - photosynthesis
KW - pyrenoid
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UR - http://www.scopus.com/inward/citedby.url?scp=85029608089&partnerID=8YFLogxK
U2 - 10.1016/j.cell.2017.08.044
DO - 10.1016/j.cell.2017.08.044
M3 - Article
C2 - 28938113
AN - SCOPUS:85029608089
SN - 0092-8674
VL - 171
SP - 133-147.e14
JO - Cell
JF - Cell
IS - 1
ER -