Chlorophyll biosynthesis under the control of arginine metabolism

ABSTRACT: In natural environments, photosynthetic organisms adjust their metabolism to cope with the fluctuating availability of combined nitrogen-sources, a growth limiting factor. For the acclimation, the dynamic degradation/synthesis of tetrapyrrolic pigments as well as of the amino acid arginine is pivotal; however, there was no evidence that these processes could be functionally coupled. Using co-immunopurification and spectral shift assays we found that in the cyanobacterium Synechocystis sp. PCC 6803 the arginine-related ArgD and CphB enzymes form protein complexes with Gun4, an essential factor for chlorophyll biosynthesis. Gun4 binds ArgD with high affinity, and the ArgD-Gun4 complex strongly accumulates in cells supplemented with ornithine, a key intermediate of the arginine pathway. Elevated ornithine levels restricted de novo synthesis of tetrapyrrolic pigments, which arrested the recovery from nitrogen deficiency. Our data reveals a direct cross-talk between tetrapyrrole biosynthesis and arginine metabolism that clarifies the importance of balancing photosynthetic pigment synthesis with nitrogen homeostasis.

INSTRUMENT(S): timsTOF Pro

ORGANISM(S): Synechocystis Sp. Pcc 6803 (ncbitaxon:1148)

SUBMITTER: Roman Sobotka  

PROVIDER: MSV000091280 | MassIVE | Tue Feb 14 07:46:00 GMT 2023

SECONDARY ACCESSION(S): PXD040117

REPOSITORIES: MassIVE