TY - JOUR TI - Principles of cellular resource allocation revealed by condition-dependent proteome profiling AU - Metzl-Raz, Eyal AU - Kafri, Moshe AU - Yaakov, Gilad AU - Soifer, Ilya AU - Gurvich, Yonat AU - Barkai, Naama A2 - Wittkopp, Patricia J VL - 6 PY - 2017 DA - 2017/08/31 SP - e28034 C1 - eLife 2017;6:e28034 DO - 10.7554/eLife.28034 UR - https://doi.org/10.7554/eLife.28034 AB - Growing cells coordinate protein translation with metabolic rates. Central to this coordination is ribosome production. Ribosomes drive cell growth, but translation of ribosomal proteins competes with production of non-ribosomal proteins. Theory shows that cell growth is maximized when all expressed ribosomes are constantly translating. To examine whether budding yeast function at this limit of full ribosomal usage, we profiled the proteomes of cells growing in different environments. We find that cells produce excess ribosomal proteins, amounting to a constant ≈8% of the proteome. Accordingly, ≈25% of ribosomal proteins expressed in rapidly growing cells does not contribute to translation. Further, this fraction increases as growth rate decreases and these excess ribosomal proteins are employed when translation demands unexpectedly increase. We suggest that steadily growing cells prepare for conditions that demand increased translation by producing excess ribosomes, at the expense of lower steady-state growth rate. KW - translation KW - transcription KW - ribosomes KW - resource allocation KW - proteome JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -