RT Journal Article
SR Electronic
T1 Principles of cellular resource allocation revealed by condition-dependent proteome profiling
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 124370
DO 10.1101/124370
A1 Eyal Metzl-Raz
A1 Moshe Kafri
A1 Gilad Yaakov
A1 Ilya Soifer
A1 Yonat Gurvich
A1 Naama Barkai
YR 2017
UL http://biorxiv.org/content/early/2017/05/01/124370.abstract
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 other 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 an excess of ribosomal proteins, amounting to a constant ≈8% of the proteome. Accordingly, ≈25% of ribosomal proteins expressed in rapidly growing cells do not contribute to translation. This fraction increases as growth rate decreases. These excess ribosomal proteins are employed during nutrient upshift or when forcing unneeded expression. 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.