Resource Sharing Controls Gene Expression Bursting.
Episodic gene expression, with periods of high expression separated by periods of no expression, is a pervasive biological phenomenon. This bursty pattern of expression draws from a finite reservoir of expression machinery in a highly time variant way, i.e., requiring no resources most of the time but drawing heavily on them during short intense bursts, that intimately links expression bursting and resource sharing. Yet, most recent investigations have focused on specific molecular mechanisms intrinsic to the bursty behavior of individual genes, while little is known about the interplay between resource sharing and global expression bursting behavior. Here, we confine Escherichia coli cell extract in both cell-sized microfluidic chambers and lipid-based vesicles to explore how resource sharing influences expression bursting. Interestingly, expression burst size, but not burst frequency, is highly sensitive to the size of the shared transcription and translation resource pools. The intriguing implication of these results is that expression bursts are more readily amplified than initiated, suggesting that burst formation occurs through positive feedback or cooperativity. When extrapolated to prokaryotic cells, these results suggest that large translational bursts may be correlated with large transcriptional bursts. This correlation is supported by recently reported transcription and translation bursting studies in E. coli. The results reported here demonstrate a strong intimate link between global expression burst patterns and resource sharing, and they suggest that bursting plays an important role in optimizing the use of limited, shared expression resources.
Bredesen Center, University of Tennessee , Knoxville, Tennessee 37996-2010, United States.|Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
Patrick M
PM
Caveney
Bredesen Center, University of Tennessee , Knoxville, Tennessee 37996-2010, United States.|Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
S Elizabeth
SE
Norred
Bredesen Center, University of Tennessee , Knoxville, Tennessee 37996-2010, United States.|Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
Charles W
CW
Chin
Bredesen Center, University of Tennessee , Knoxville, Tennessee 37996-2010, United States.|Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.|Department of Biomedical Engineering and Mechanics, Virginia Tech , Blacksburg, Virginia 24061, United States.
Jonathan B
JB
Boreyko
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.|Laboratory of Immune Cell Epigenetics and Signaling, The Rockefeller University , New York, New York 10065, United States.
Brandon S
BS
Razooky
Bredesen Center, University of Tennessee , Knoxville, Tennessee 37996-2010, United States.|Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.|Biosciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
Scott T
ST
Retterer
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
C Patrick
CP
Collier
Bredesen Center, University of Tennessee , Knoxville, Tennessee 37996-2010, United States.|Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.|Joint Institute for Biological Sciences, University of Tennessee-Knoxville and Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
Michael L
ML
Simpson
D002474:Cell-Free System; D004926:Escherichia coli / Q000235:genetics*; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics; D007091:Image Processing, Computer-Assisted; D044085:Microfluidics / Q000295:instrumentation; D008957:Models, Genetic; D012333:RNA, Messenger
D012333:RNA, Messenger; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins
bursting; cell-free; confinement; gene expression; microfluidics; resource sharing