Synthesis and degradation of nitrate reductase during the cell cycle of Chlorella sorokiniana

• Published in: Plant physiology (Bethesda) Vol. 89; no. 1; pp. 220 - 224
• Main Authors: Velasco, P.J, Tischner, R, Huffaker, R.C, Whitaker, J.R
• Format: Journal Article
• Language: English
• Published: Legacy CDMS American Society of Plant Physiologists 01.01.1989
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Biological and medical sciences; BIOLOGICAL RHYTHMS; biosynthesis; cell cycle; Cell Cycle - physiology; Cell growth; Chlorella - cytology; Chlorella - enzymology; Chlorella - metabolism; Chlorella sorokiniana; CHLOROPHYCEAE; CICLO VITAL; CYCLE DE DEVELOPPEMENT; DEGRADATION; DETERIORO; diurnal variations; Electrophoresis; Enzyme activity; Enzymes; ENZYMIC ACTIVITY; Fundamental and applied biological sciences. Psychology; Gels; Herbicides - metabolism; LIFE CYCLE; Life Sciences (General); Light; light effects; Metabolism; Metabolism and Enzymology; NAD - metabolism; NADH Dehydrogenase - metabolism; nitrate reductase; Nitrate Reductases - analysis; Nitrate Reductases - biosynthesis; Nitrate Reductases - metabolism; Nitrates; OXIDOREDUCTASES; OXIDORREDUCTASAS; OXYDOREDUCTASE; Paraquat - metabolism; Photoperiod; Physiological assimilation; Physiological regulation; Plant physiology and development; Plant Proteins - analysis; Plant Proteins - biosynthesis; Plant Proteins - metabolism; Radioactive decay; RITMOS BIOLOGICOS; RYTHME BIOLOGIQUE; Scotophase; Non-Nasa Center; Nasa Discipline Life Support Systems; Proteins; Light effect; Enzymatic activity; Enzyme; Algae; Chlorophycophyta; Electrophoresis; Biosynthesis; Catabolism; Thallophyta; NASA Discipline Life Support Systems; Non-NASA Center
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.89.1.220

Studies on the diurnal variations of nitrate reductase (NR) activity during the life cycle of synchronized Chlorella sorokiniana cells grown with a 7:5 light-dark cycle showed that the NADH:NR activity, as well as the NR partial activities NADH:cytochrome c reductase and reduced methyl viologen:NR, closely paralleled the appearance and disappearance of NR protein as shown by sodium dodecyl sulfate gel electrophoresis and immunoblots. Results of pulse-labeling experiments with [35S]methionine further confirmed that diurnal variations of the enzyme activities can be entirely accounted for by the concomitant synthesis and degradation of the NR protein.