Contagious Aggregation: Transmittable Protein Aggregation in Cellular Communities Initiated by Synthetic Cells

Development of multifunctional quaternary ammonium cellulose coating for fruit preservation

Due to the lack of preservation technology and cold chain logistics, the decay loss rate of fruits and vegetables is surprisingly high. To meet the demands of environmental protection and food preservation, sustainable coating materials that fabricated by biowaste to wealth approach can efficiently cover the challenges. Hence, quaternary ammonium lotus root residue celluloses (QACs) were homogeneously synthesized by reacting cellulose with 3-chloro-2-hydroxypropyltrimethylammonium chloride for 24 h. In terms of the chemical structure, morphology, rheological property and biocompatibility as well as antimicrobial ability, QACs were characterized. The antibacterial mechanism was investigated at cellular level via disruption of membrane integrity, metabolic inactivation, destruction of antioxidant system. Meanwhile, due to the nature source of cellulose, QACs exhibited inherent outstanding biocompatibility. QACs could extend preservation time of strawberry for least 3 d by decreasing the weight loss and maintaining the hardness and springiness, as well as inhibit the growth of pathogenic bacteria. The residual amount of QACs coating on the surface of strawberries was <0.1 mg kg-1, featuring with easy cleaning and safety. This biowaste-derived coating for strawberry preservation not only provides a new strategy for fruit preservation platforms but also expands the high-value application of biowaste resources in the agro-industry.

Aggregation of rhodopsin mutants in mouse models of autosomal dominant retinitis pigmentosa

Mutations in rhodopsin can cause it to misfold and lead to retinal degeneration. A distinguishing feature of these mutants in vitro is that they mislocalize and aggregate. It is unclear whether or not these features contribute to retinal degeneration observed in vivo. The effect of P23H and G188R misfolding mutations were examined in a heterologous expression system and knockin mouse models, including a mouse model generated here expressing the G188R rhodopsin mutant. In vitro characterizations demonstrate that both mutants aggregate, with the G188R mutant exhibiting a more severe aggregation profile compared to the P23H mutant. The potential for rhodopsin mutants to aggregate in vivo was assessed by PROTEOSTAT, a dye that labels aggregated proteins. Both mutants mislocalize in photoreceptor cells and PROTEOSTAT staining was detected surrounding the nuclei of photoreceptor cells. The G188R mutant promotes a more severe retinal degeneration phenotype and greater PROTEOSTAT staining compared to that promoted by the P23H mutant. Here, we show that the level of PROTEOSTAT positive cells mirrors the progression and level of photoreceptor cell death, which suggests a potential role for rhodopsin aggregation in retinal degeneration.

A Self-Regenerating Artificial Cell, that is One Step Closer to Living Cells: Challenges and Perspectives

Controllable, self-regenerating artificial cells (SRACs) can be a vital advancement in the field of synthetic biology, which seeks to create living cells by recombining various biological molecules in the lab. This represents, more importantly, the first step on a long journey toward creating reproductive cells from rather fragmentary biochemical mimics. However, it is still a difficult task to replicate the complex processes involved in cell regeneration, such as genetic material replication and cell membrane division, in artificially created spaces. This review highlights recent advances in the field of controllable, SRACs and the strategies to achieve the goal of creating such cells. Self-regenerating cells start by replicating DNA and transferring it to a location where proteins can be synthesized. Functional but essential proteins must be synthesized for sustained energy generation and survival needs and function in the same liposomal space. Finally, self-division and repeated cycling lead to autonomous, self-regenerating cells. The pursuit of controllable, SRACs will enable authors to make bold advances in understanding life at the cellular level, ultimately providing an opportunity to use this knowledge to understand the nature of life.

Synthetic Monosaccharide Channels: Size-Selective Transmembrane Transport of Glucose and Fructose Mediated by Porphyrin Boxes

Here we report synthetic monosaccharide channels built with shape-persistent organic cages, porphyrin boxes (PBs), that allow facile transmembrane transport of glucose and fructose through their windows. PBs show a much higher transport rate for glucose and fructose over disaccharides such as sucrose, as evidenced by intravesicular enzyme assays and molecular dynamics simulations. The transport rate can be modulated by changing the length of the alkyl chains decorating the cage windows. Insertion of a linear pillar ligand into the cavity of PBs blocks the monosaccharide transport. In vitro cell experiment shows that PBs transport glucose across the living-cell membrane and enhance cell viability when the natural glucose transporter GLUT1 is blocked. Time-dependent live-cell imaging and MTT assays confirm the cyto-compatibility of PBs. The monosaccharide-selective transport ability of PBs is reminiscent of natural glucose transporters (GLUTs), which are crucial for numerous biological functions.