title: Probing circadian rhythms in Chlamydomonas rheinhardtii by functional proteomics.
abstract: In the unicellular flagellated green alga Chlamydomonas reinhardtii several processes are regulated by the circadian clock. To study circadian controlled processes, the cell's clock is synchronized in a 12 h light-12 h dark cycle (LD12:12) before the cells are released into constant conditions of dim light and temperature. Under these free-running conditions circadian rhythms will continue with a period of about 24 h and cells can be harvested during specific time-points of subjective day and night. These cells were then used for isolating basic proteins by heparin-affinity chromatography, separating them on two-dimensional PAGE and comparing the amount of their expression at four different time-points of subjective day and night. Among 230 proteins, we could find two proteins whose expression level changed more than fourfold throughout the circadian cycle. These proteins were identified as a protein disulfide isomerase (PDI)-like protein and a tetratricopeptide repeat (TPR) protein by liquid-chromatography-electrospray ionization mass spectrometry (LC-ESI-MS).
authors.affiliation: Institut für Allgemeine Botanik, Friedrich-Schiller-Universität Jena, Jena, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Wagner
authors.forename: Maria
authors.initials: M
authors.lastname: Mittag
mesh_terms: D020418:Algal Proteins / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D002696:Chlamydomonas / Q000378:metabolism*; D002853:Chromatography, Liquid; D002940:Circadian Rhythm / Q000502:physiology*; D015180:Electrophoresis, Gel, Two-Dimensional; D040901:Proteomics / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D020418:Algal Proteins