SAGA1 and MITH1 produce matrix-traversing membranes in the CO₂-fixing pyrenoid.

ABSTRACT: Approximately one-third of global CO₂ assimilation is performed by the pyrenoid, a liquid-like organelle found in most algae and some plants. Specialized pyrenoid-traversing membranes are hypothesized to drive CO₂ assimilation in the pyrenoid by delivering concentrated CO₂, but how these membranes are made to traverse the pyrenoid matrix remains unknown. Here we show that proteins SAGA1 and MITH1 cause membranes to traverse the pyrenoid matrix in the model alga Chlamydomonas reinhardtii. Mutants deficient in SAGA1 or MITH1 lack matrix-traversing membranes and exhibit growth defects under CO₂-limiting conditions. Expression of SAGA1 and MITH1 together in a heterologous system, the model plant Arabidopsis thaliana, produces matrix-traversing membra

SUBMITTER: Hennacy JH 

PROVIDER: S-EPMC11649565 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature