Microtubule networks support many cellular processes and exhibit a highly ordered architecture.However,due to the limited axial resolution of conventional light microscopy,the structural features of these networks can...Microtubule networks support many cellular processes and exhibit a highly ordered architecture.However,due to the limited axial resolution of conventional light microscopy,the structural features of these networks cannot be resolved in three-dimensional(3D)space.Here,we used customized ultra-high-resolution interferometric single-molecule localization microscopy to characterize the microtubule networks in Caco2 cells.We found that the calmodulin-regulated spectrin-associated proteins(CAMSAPs)localize at a portion of microtubule intersections.Further investigation showed that depletion of CAMSAP2 and CAMSAP3 leads to the narrowing of the inter-microtubule distance.Mechanistically,CAMSAPs recognize microtubule defects,which often occur near microtubule intersections,and then recruit katanin to remove the damaged microtubules.Therefore,the CAMSAP–katanin complex is a regulatory module for the distance between microtubules.Taken together,our results characterize the architecture of cellular microtubule networks in high resolution and provide molecular insights into how the 3D structure of microtubule networks is controlled.展开更多
基金funded by the National Natural Science Foundation of China(31930025,31922018,and 3227073)the National Key Research and Development Program of China(2021YFA0804802 and 2018YFA0801104)X.L.was supported by the IDG/McGovern Institute for Brain Research at Tsinghua University.
文摘Microtubule networks support many cellular processes and exhibit a highly ordered architecture.However,due to the limited axial resolution of conventional light microscopy,the structural features of these networks cannot be resolved in three-dimensional(3D)space.Here,we used customized ultra-high-resolution interferometric single-molecule localization microscopy to characterize the microtubule networks in Caco2 cells.We found that the calmodulin-regulated spectrin-associated proteins(CAMSAPs)localize at a portion of microtubule intersections.Further investigation showed that depletion of CAMSAP2 and CAMSAP3 leads to the narrowing of the inter-microtubule distance.Mechanistically,CAMSAPs recognize microtubule defects,which often occur near microtubule intersections,and then recruit katanin to remove the damaged microtubules.Therefore,the CAMSAP–katanin complex is a regulatory module for the distance between microtubules.Taken together,our results characterize the architecture of cellular microtubule networks in high resolution and provide molecular insights into how the 3D structure of microtubule networks is controlled.
