Prions are infectious proteins that mostly replicate in self-propagating amyloid conformations (filamentous protein polymers) and consist of structurally altered normal soluble proteins. Prions can arise spontaneously in the cell without any clear reason and are generally considered fatal disease-causing agents that are only present in mammals. However, after the seminal discovery of two prions, [PSI+] and [URE3], in the eukaryotic model microorganism Saccharomyces cerevisiae, at least ten more prions have been discovered, and their biological and pathological effects on the host, molecular structure, and the relationship between prions and cellular components have been studied. In a filamentous fungus model, Podospora anserina, a vegetative incomparability-related [Het-s] prion that directly triggers cell death during anastomosis (hyphal fusion) was discovered. These prions in eukaryotic microbes have extended our understanding to overcome most fatal human prion/amyloid diseases. A prokaryotic microorganism (Clostridium botulinum) was reported to have a prion analog. The transcriptional regulators of C. botulinum-Rho can be converted into the self-replicating prion form ([RHO-X-C+]), which may affect global transcription. Here, we outline the major issues with prions in microbes and the lessons learned from the relatively uncovered microbial prion world.

朊病毒是一种传染性蛋白质，主要以自我繁殖的淀粉样蛋白构象（丝状蛋白质聚合物）复制，并由结构改变的正常可溶性蛋白质组成。朊病毒可以在没有任何明确原因的情况下在细胞中自发产生，通常被认为是仅存在于哺乳动物中的致命致病因子。然而，在真核模型微生物酿酒酵母中开创性地发现了两种朊病毒[PSI+]和[URE3]之后，至少又发现了十种朊病毒，以及它们对宿主、分子结构和微生物的生物学和病理作用。朊病毒和细胞成分之间的关​​系已被研究。在丝状真菌模型中，发现了一种与营养不可比性相关的[Het-s]朊病毒，它在吻合（菌丝融合）过程中直接触发细胞死亡。真核微生物中的这些朊病毒扩展了我们的认识，以克服大多数致命的人类朊病毒/淀粉样蛋白疾病。据报道，原核微生物（肉毒梭菌）具有朊病毒类似物。肉毒杆菌-Rho的转录调节因子可以转化为自我复制的朊病毒形式（[RHO- X -C+]），这可能会影响整体转录。在这里，我们概述了微生物中朊病毒的主要问题以及从相对未知的微生物朊病毒世界中吸取的教训。