1. A Deg-protease family protein in marine Synechococcus is involved in outer membrane protein organization
- Author
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B. Brahamsha, Brian Palenik, and Rhona K. Stuart
- Subjects
Proteases ,lcsh:QH1-199.5 ,medicine.medical_treatment ,Deg protease ,Mutant ,Ocean Engineering ,Aquatic Science ,lcsh:General. Including nature conservation, geographical distribution ,Oceanography ,03 medical and health sciences ,medicine ,Marine Science ,14. Life underwater ,envelope stress ,lcsh:Science ,030304 developmental biology ,Water Science and Technology ,Marine Synechococcus ,0303 health sciences ,Global and Planetary Change ,Protease ,biology ,Strain (chemistry) ,copper tolerance ,030306 microbiology ,phosphate stress ,Synechocystis ,biology.organism_classification ,Synechococcus ,Biochemistry ,copper ,Alkaline phosphatase ,lcsh:Q ,Bacterial outer membrane - Abstract
Deg-family proteases are a periplasm-associated group of proteins that are known to be involved in envelope stress responses and are found in most microorganisms. Orthologous genes SYNW2176 (in strain WH8102) and sync_2523 (strain CC9311) are predicted members of the Deg-protease family and are among the few genes induced by copper stress in both open ocean and coastal marine Synechococcus strains. In contrast to the lack of a phenotype in a similar knockout in Synechocystis PCC6803, a SYNW2176 knockout mutant in strain WH8102 was much more resistant to copper than the wild-type. The mutant also exhibited a significantly altered outer membrane protein composition which may contribute to copper resistance, longer lag phase after transfer, low-level consistent alkaline phosphatase activity, and an inability to induce high alkaline phosphatase activity in response to phosphate stress. This phenotype suggests a protein-quality-control role for SYNW2176, the absence of which leads to a constitutively activated stress response. Deg-protease family proteins in this ecologically important cyanobacterial group thus help to determine outer membrane responses to both nutrients and toxins.
- Published
- 2014