[en] The green microalga C. reinhardtii can grow heterotrophically in presence of acetate in the dark as sole carbon
source, due to the anaplerotic pathway of glyoxylate cycle1 almost completely localised in the peroxisomal
microbodies2 . Despite the significant advances gained on carbon metabolism, the genes involved in acetate
transport are not yet identified. Recently, five functionally uncharacterized members predicted to have
transporter-like structure were classified within the protein family GPR1/FUN34/YaaH(/SatP) (GFY)3, which
comprises genes coding for putative carboxylic acids transporters in other microorganisms, including acetate as
substrate4. In C. reinhardtii, GFY1-5 as we shown by YFP fusion protein, localise to peroxisomal membranes. In
addition, we also showed that these genes present distinct expression patterns in different cultivation
conditions, which correlates with associated co-expressed genes found in the databases. Therefore, although
these proteins share between 78 and 97% similarity between their amino acid sequences, this might suggest
non-redundant roles. To gain insight on their role, we are currently analysing insertional and knock-down
mutants. Mutants for the genes GFY1, GFY2 and GFY3 were obtained from the Chlamydomonas Library Project 5.
Mutants for GFY4, GFY5 and all GFY genes are presently under generation via artificial micro RNA. In conclusion,
GFY members could represent different protagonists in transporting substrates in/out of peroxisomal
microbodies, as putative transporters/permeases function.