Ghag Siddhesh B, D'Souza Jacinta S
School of Biological Sciences, UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai Campus, Kalina, Santacruz (E), Mumbai, 400098, India.
Arch Microbiol. 2022 Jul 21;204(8):511. doi: 10.1007/s00203-022-03130-2.
Cyanobacteria are a large group of ubiquitously found photosynthetic prokaryotes that are constantly exposed to different kinds of stressors of varying intensities and seem to overcome these in a precise and regulated manner. However, a high dose and duration of given stress induce cell death in a few select cyanobacteria, mainly to protect other cells (altruism). Despite the recent findings for the presence of biochemical and molecular hallmarks of cell death in cyanobacteria, it is yet a sketchily understood phenomenon. Regulation of metacaspase-like genes during Programmed Cell Death suggests it to be a genetically controlled mechanism like other eukaryotes. In addition to providing a comprehensive understanding of the current status of cell death in cyanobacteria, this review has used in silico analyses to directly compare the existence of some important molecular players operating in the intrinsic and extrinsic apoptotic pathways. Phylogenetic trees for all sequences indicate a cluster with a common ancestry and also a divergence from sequences of eukaryotic origin. To the best of our knowledge, such a comparison (except for orthocaspases) has not been attempted earlier and hopes to encourage workers in the field to investigate this altruistic phenomenon in detail.
蓝细菌是一类广泛存在的光合原核生物，它们经常暴露于不同强度的各种应激源下，并且似乎能以精确且受调控的方式克服这些应激。然而，特定应激的高剂量和持续时间会在少数特定的蓝细菌中诱导细胞死亡，主要是为了保护其他细胞（利他行为）。尽管最近发现蓝细菌中存在细胞死亡的生化和分子特征，但这仍是一个了解甚少的现象。程序性细胞死亡过程中类metacaspase基因的调控表明，它是一种像其他真核生物一样受基因控制的机制。除了全面了解蓝细菌细胞死亡的现状外，本综述还利用计算机分析直接比较了在内在和外在凋亡途径中发挥作用的一些重要分子参与者的存在情况。所有序列的系统发育树表明存在一个具有共同祖先的聚类，并且与真核生物起源的序列存在差异。据我们所知，此前尚未尝试过这种比较（除了orthocaspases），希望能鼓励该领域的研究人员详细研究这种利他现象。
