Molecular analysis and control of cysteine biosynthesis: integration of nitrogen and sulphur metabolism.
Since cysteine is the first committed molecule in plant metabolism containing both sulphur and nitrogen, the regulation of its biosynthesis is critically important. Cysteine itself is required for the production of an abundance of key metabolites in diverse pathways. Plants alter their metabolism to compensate for sulphur and nitrogen deficiencies as best as they can, but limitations in either nutrient not only curb a plant's ability to synthesize cysteine, but also restrict protein synthesis. Nutrients such as nitrate and sulphate (and carbon) act as signals; they trigger molecular mechanisms that modify biosynthetic pathways and thereby have a profound impact on metabolite fluxes. Cysteine biosynthesis is modified by regulators acting at the site of uptake and throughout the plant system. Recent data point to the existence of nutrient-specific signal transduction pathways that relay information about external and internal nutrient concentrations, resulting in alterations to cysteine biosynthesis. Progress in this field has led to the cloning of genes that play pivotal roles in nutrient-induced changes in cysteine formation.
Hesse
Holger
H
Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department of Molecular Physiology, Am Muehlenberg 1, D-14476 Golm, Germany. hesse@mpimp-golm.mpg.de
Nikiforova
Victoria
V
Gakière
Bertrand
B
Hoefgen
Rainer
R
D002352:Carrier Proteins / Q000378:metabolism; D003545:Cysteine / Q000096:biosynthesis*; D026901:Membrane Transport Proteins; D009566:Nitrates / Q000494:pharmacology; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D000076988:Sulfate Transporters; D013431:Sulfates / Q000494:pharmacology; D013455:Sulfur / Q000737:chemistry / Q000378:metabolism*
D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D009566:Nitrates; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; D013431:Sulfates; D013455:Sulfur; D050862:Oxidoreductases Acting on Sulfur Group Donors; C019618:adenylylsulfate reductase; D003545:Cysteine; D009584:Nitrogen