Department of Cell Biochemistry, University of Groningen, Groningen, The Netherlands.
PLoS One. 2021 Feb 11;16(2):e0246345. doi: 10.1371/journal.pone.0246345. eCollection 2021.
Amoeboid cells constantly change shape and extend protrusions. The direction of movement is not random, but is correlated with the direction of movement in the preceding minutes. The basis of this correlation is an underlying memory of direction. The presence of memory in movement is known for many decades, but its molecular mechanism is still largely unknown. This study reports in detail on the information content of directional memory, the kinetics of learning and forgetting this information, and the molecular basis for memory using Dictyostelium mutants. Two types of memory were characterized. A short-term memory stores for ~20 seconds the position of the last pseudopod using a local modification of the branched F-actin inducer SCAR/WAVE, which enhances one new pseudopod to be formed at the position of the previous pseudopod. A long term memory stores for ~2 minutes the activity of the last ~10 pseudopods using a cGMP-binding protein that induces myosin filaments in the rear of the cell; this inhibits pseudopods in the rear and thereby enhances pseudopods in the global front. Similar types of memory were identified in human neutrophils and mesenchymal stem cells, the protist Dictyostelium and the fungus B.d. chytrid. The synergy of short- and long-term memory explains their role in persistent movement for enhanced cell dispersal, food seeking and chemotaxis.
变形细胞不断改变形状并伸出突起。运动的方向不是随机的，而是与前几分钟的运动方向相关。这种相关性的基础是潜在的方向记忆。运动中的记忆已经存在了几十年，但它的分子机制在很大程度上仍然未知。本研究详细报告了方向记忆的信息含量、学习和遗忘信息的动力学以及使用 Dictyostelium 突变体的记忆的分子基础。两种类型的记忆被描述。短期记忆使用局部修饰的分支 F-肌动蛋白诱导物 SCAR/WAVE 存储最近一次伪足的位置约 20 秒，该修饰物增强一个新的伪足在前一个伪足的位置形成。长期记忆使用 cGMP 结合蛋白存储最近 10 个伪足的活动约 2 分钟，该蛋白在后细胞中诱导肌球蛋白丝；这抑制了后部的伪足，从而增强了整体前部的伪足。在人类中性粒细胞和间充质干细胞、原生动物 Dictyostelium 和真菌 B.d.chytrid 中也发现了类似类型的记忆。短期和长期记忆的协同作用解释了它们在持续运动中的作用，以增强细胞扩散、觅食和趋化性。
