摘要：Proliferating cell nuclear antigen (PCNA), encoded by POL30 in Saccharomyces cerevisiae, is a key component of DNA metabolism. Here, a library consisting of 304 PCNA mutants was designed and constructed to probe the contribution of each residue to the biological function of PCNA. Five regions with elevated sen sitivity to DNA damaging reagents were identified using high-throughput phe no type screening. Using a series of genetic and biochemical analyses, we demonstrated that one particular mutant, K168A, has defects in the DNA damage tolerance (DDT) pathway by disrupting the interaction between PCNA and Rad5. Subsequent domain analysis showed that the PCNA-Rad5 interaction is a prerequisite for the function of Rad5 in DDT. Our study not only provides a resource in the form of a library of versatile mutants to study the functions of PCNA, but also reveals a key residue on PCNA (K168) which highlights the importance of the PCNA-Rad5 interaction in the template switching (TS) pathway.

摘要：Plants adapt to their changing environments by sensing and responding to physical,biological,and chemical *** to their sessile lifestyles,plants experience a vast array of external stimuli and selectively perceive and respond to specific *** repurposing the logic circuitry and biological and molecular components used by plants in nature,genetically encoded plant-based biosensors(GEPBs)have been developed by directing signal recognition mechanisms into carefully assembled outcomes that are easily *** allow for in vivo monitoring of biological processes in plants to facilitate basic studies of plant growth and *** are also useful for environmental monitoring,plant abiotic and biotic stress management,and accelerating design-build-test-learn cycles of plant *** the advent of synthetic biology,biological and molecular components derived from alternate natural organisms(e.g.,microbes)and/or de novo parts have been used to build *** this review,we summarize the framework for engineering different types of *** then highlight representative validated biological components for building plant-based biosensors,along with various applications of plant-based biosensors in basic and applied plant science ***,we discuss challenges and strategies for the identification and design of biological components for plant-based biosensors.