Compartmentation
of proteins into biomolecular condensates or membraneless
organelles formed by phase separation is an emerging principle for
the regulation of cellular processes. Creating synthetic condensates
that accommodate specific intracellular proteins on demand would have
various applications in chemical biology, cell engineering, and synthetic
biology. Here, we report the construction of synthetic protein condensates
capable of recruiting and/or releasing proteins of interest in living
mammalian cells in response to a small molecule or light. By a modular
combination of a tandem fusion of two oligomeric proteins, which forms
phase-separated synthetic protein condensates in cells, with a chemically
induced dimerization tool, we first created a chemogenetic protein
condensate system that can rapidly recruit target proteins from the
cytoplasm to the condensates by addition of a small-molecule dimerizer.
We next coupled the protein-recruiting condensate system with an engineered
proximity-dependent protease, which gave a second protein condensate
system wherein target proteins previously expressed inside the condensates
are released into the cytoplasm by small-molecule-triggered protease
recruitment. Furthermore, an optogenetic condensate system that allows
reversible release and sequestration of protein activity in a repeatable
manner using light was constructed successfully. These condensate
systems were applicable to control protein activity and cellular processes
such as membrane ruffling and ERK signaling in a time scale of minutes.
This proof-of-principle work provides a new platform for chemogenetic
and optogenetic control of protein activity in mammalian cells and
represents a step toward tailor-made engineering of synthetic protein
condensate-based soft materials with various functionalities for biological
and biomedical applications.
Dysfunction of ribosome biogenesis induces divergent ribosome-related diseases including ribosomopathy and occasionally results in carcinogenesis. Although many defects in ribosome-related genes have been investigated, little is known about contribution of ribosomal RNA (rRNA) in ribosome-related disorders. Meanwhile, microRNA (miRNA), an important regulator of gene expression, is derived from both coding and noncoding region of the genome and is implicated in various diseases. Therefore, we performed in silico analyses using M-fold, TargetScan, GeneCoDia3, and so forth to investigate RNA relationships between rRNA and miRNA against cellular stresses. We have previously shown that miRNA synergism is significantly correlated with disease and the miRNA package is implicated in memory for diseases; therefore, quantum Dynamic Nexus Score (DNS) was also calculated using MESer program. As a result, seventeen RNA sequences identical with known miRNAs were detected in the human rRNA and termed as rRNA-hosted miRNA analogs (rmiRNAs). Eleven of them were predicted to form stem-loop structures as pre-miRNAs, and especially one stem-loop was completely identical with hsa-pre-miR-3678 located in the non-rDNA region. Thus, these rmiRNAs showed significantly high DNS values, participation in regulation of cancer-related pathways, and interaction with nucleolar RNAs, suggesting that rmiRNAs may be stress-responsible resident miRNAs which transmit stress-tuning information in multiple levels.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.