Ca2+/calmodulin-dependent protein kinase II β (CaMKIIβ) decodes ER Ca2+ transients to trigger autophagosome formation. Qiaoxia Zheng et al.

These are unprocessed and uncompressed imaging data (microscopy as well as gels and blots) of the study "Ca2+/calmodulin-dependent protein kinase II β (CaMKIIβ) decodes ER Ca2+ transients to trigger autophagosome formation". In this study, we focused on how Ca2+ transients on the ER outer surface elicited by autophagy stimuli are sustained and decoded to trigger autophagosome formation in multicellular organisms. Here we show that CaMKIIβ integrates ER Ca2+ transients to trigger liquid-liquid phase separation (LLPS) of the autophagosome-initiating FIP200 complex. In response to ER Ca2+ transients, CaMKIIβ is recruited from actin filaments and forms condensates, which serve as sites for emergence of or interaction with FIP200 puncta. CaMKIIβ phosphorylates FIP200 at Thr269, Thr1127 and Ser1484 to modulate LLPS and properties of the FIP200 complex, thereby controlling its function in autophagosome formation. CaMKIIβ also controls the amplitude, duration and propagation of ER Ca2+ transients during autophagy induction. CaMKIIβ mutations identified in the neurodevelopmental disorder MRD54 affect the function of CaMKIIβ in autophagy. Our study reveals that CaMKIIβ is essential for sustaining and decoding ER Ca2+ transients to specify autophagosome formation in metazoans.本数据集包含研究《Ca2+/钙调蛋白依赖性蛋白激酶IIβ（CaMKIIβ）解码内质网（Endoplasmic Reticulum, ER）Ca2+瞬变以触发自噬体（autophagosome）形成》的未处理、未压缩成像数据，涵盖显微成像数据以及凝胶、印迹数据。本研究聚焦于多细胞生物中，自噬刺激诱导的内质网外表面Ca2+瞬变的维持与解码机制，及其如何触发自噬体形成。本研究发现，CaMKIIβ可整合内质网Ca2+瞬变信号，进而触发自噬起始因子FIP200复合物（FIP200 complex）的液液相分离（liquid-liquid phase separation, LLPS）。在受到内质网Ca2+瞬变刺激时，CaMKIIβ从肌动蛋白丝（actin filaments）上被招募并形成凝聚体，该凝聚体可作为FIP200斑点出现或与之相互作用的位点。CaMKIIβ可在苏氨酸269（Thr269）、苏氨酸1127（Thr1127）以及丝氨酸1484（Ser1484）位点对FIP200进行磷酸化，以此调控FIP200复合物的液液相分离与自身特性，进而控制其在自噬体形成过程中的功能。此外，CaMKIIβ还可调控自噬诱导阶段内质网Ca2+瞬变的振幅、持续时间与传播范围。在神经发育障碍MRD54中鉴定到的CaMKIIβ突变，会损害其在自噬过程中的功能。本研究揭示，在后生动物（metazoans）中，CaMKIIβ对于维持并解码内质网Ca2+瞬变信号，以明确自噬体形成的进程至关重要。