title: Synchronous protein cycling in batch cultures of the yeast Saccharomyces cerevisiae at log growth phase.
abstract: The assumption that cells are temporally organized systems, i.e. showing relevant dynamics of their state variables such as gene expression or protein and metabolite concentration, while tacitly given for granted at the molecular level, is not explicitly taken into account when interpreting biological experimental data. This conundrum stems from the (undemonstrated) assumption that a cell culture, the actual object of biological experimentation, is a population of billions of independent oscillators (cells) randomly experiencing different phases of their cycles and thus not producing relevant coordinated dynamics at the population level. Moreover the fact of considering reproductive cycle as by far the most important cyclic process in a cell resulted in lower attention given to other rhythmic processes. Here we demonstrate that growing yeast cells show a very repeatable and robust cyclic variation of the concentration of proteins with different cellular functions. We also report experimental evidence that the mechanism governing this basic oscillator and the cellular entrainment is resistant to external chemical constraints. Finally, cell growth is accompanied by cyclic dynamics of medium pH. These cycles are observed in batch cultures, different from the usual continuous cultures in which yeast metabolic cycles are known to occur, and suggest the existence of basic, spontaneous, collective and synchronous behaviors of the cell population as a whole.
authors: Dept. of Biology and Biotechnology 'Charles Darwin', Sapienza Università di Roma, Rome, Italy. gabriele.biotek@gmail.com
authors: Gabriele
authors: G
authors: Romagnoli
authors: Enrico
authors: E
authors: Cundari
authors: Rodolfo
authors: R
authors: Negri
authors: Marco
authors: M
authors: Crescenzi
authors: Lorenzo
authors: L
authors: Farina
authors: Alessandro
authors: A
authors: Giuliani
authors: Michele M
authors: MM
authors: Bianchi
mesh_terms: D061249:Batch Cell Culture Techniques / Q000379:methods*; D002453:Cell Cycle / Q000235:genetics; D049109:Cell Proliferation; D003513:Cycloheximide / Q000494:pharmacology; D004265:DNA Helicases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014638:Vanadates / Q000378:metabolism
chemical_list: D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C027937:ribosomal protein L16; D014638:Vanadates; D003513:Cycloheximide; C506739:MGS1 protein, S cerevisiae; D004265:DNA Helicases