5 research outputs found
Effects of the DNA state fluctuation on single-cell dynamics of self-regulating gene
A dynamical mean-field theory is developed to analyze stochastic single-cell
dynamics of gene expression. By explicitly taking account of nonequilibrium and
nonadiabatic features of the DNA state fluctuation, two-time correlation
functions and response functions of single-cell dynamics are derived. The
method is applied to a self-regulating gene to predict a rich variety of
dynamical phenomena such as anomalous increase of relaxation time and
oscillatory decay of correlations. Effective "temperature" defined as the ratio
of the correlation to the response in the protein number is small when the DNA
state change is frequent, while it grows large when the DNA state change is
infrequent, indicating the strong enhancement of noise in the latter case.Comment: 18 pages, 5 figure
Sphingomyelin synthase 1 supports two steps of rubella virus life cycle
Summary: Our knowledge of the regulatory mechanisms that govern the replication of the rubella virus (RV) in human cells is limited. To gain insight into the host-pathogen interaction, we conducted a loss-of-function screening using the CRISPR-Cas9 system in the human placenta-derived JAR cells. We identified sphingomyelin synthase 1 (SGMS1 or SMS1) as a susceptibility factor for RV infection. Genetic knockout of SGMS1 rendered JAR cells resistant to infection by RV. The re-introduction of SGMS1 restored cellular susceptibility to RV infection. The restricted step of RV infection was post-endocytosis processes associated with the endosomal acidification. In the late phase of the RV replication cycle, the maintenance of viral persistence was disrupted, partly due to the attenuated viral gene expression. Our results shed light on the unique regulation of RV replication by a host factor during the early and late phases of viral life cycle