Activation and de novo synthesis of hydrogenase in Chlamydomonas

Journal Article · Sat Dec 01 04:00:00 EST 1984 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.76.4.1086· OSTI ID:6101472

Roessler, P G; Lien, S

Two distinct processes are involved in the formation of active hydrogenase during anaerobic adaptation of Chlamydomonas reinhardtii cells. In the first 30 minutes of anaerobiosis, nearly all of the hydrogenase activity can be attributed to activation of constituitive polypeptide precursor, based on the insensitivity of the process to treatment with cycloheximide (15 micrograms per milliliter). This concentration of cycloheximide inhibits protein synthesis by greater than 98%. After the initial activation period, de novo protein synthesis plays a critical role in the adaptation process since cycloheximide inhibits the expression of hydrogenase in maximally adapted cells by 70%. Chloramphenicol (500 micrograms per milliliter) has a much lesser effect on the adaptation process. Incubation of cell-free extracts under anaerobic conditions in the presence of dithionite, dithiothreitol, NADH, NADP, ferredoxin, ATP, Mg/sup 2 +/, Ca/sup 2 +/, and iron does not lead to active hydrogenase formation. Furthermore, in vivo reactivation of oxygen-inactivated hydrogenase does not appear to take place. The adaptation process is very sensitive to the availability of iron. Iron-deficient cultures lose the ability to form active hydrogenase before growth, photosynthesis, and respiration are significantly affected. Preincubation of iron-deficient cells with iron 2 hours prior to the adaptation period fully restores the capacity of the cells to synthesize functional hydrogenase.

• Research Organization: Solar Energy Research Inst., Golden, CO
• DOE Contract Number: AC02-83CH10093
• OSTI ID: 6101472
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 76:4; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ALGAE
ALKALINE EARTH METALS
ANAEROBIC CONDITIONS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
ATP
BIOLOGICAL ADAPTATION
BIOSYNTHESIS
CALCIUM
CHLAMYDOMONAS
CHLORAMPHENICOL
COENZYMES
CYCLOHEXIMIDE
DITHIOLS
DRUGS
ELEMENTS
ENZYME ACTIVITY
ENZYMES
FERREDOXIN
FUNGICIDES
HYDROGENASES
INHIBITION
IRON
MAGNESIUM
METABOLISM
METALLOPROTEINS
METALS
MICROORGANISMS
NADP
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDOREDUCTASES
PESTICIDES
PLANTS
PROTEINS
REAGENTS
SYNTHESIS
THIOLS
TRANSITION ELEMENTS
UNICELLULAR ALGAE