The resolution of single molecule localization imaging techniques largely depends on the precision of localization algorithms.However,the commonly used Gaussian function is not appropriate for anisotropic dipoles because it is not the true point spread function.We derived the theoretical point spread function of tilted dipoles with restricted mobility and developed an algorithm based on an artifi cial neural network for estimating the localization,orientation and mobility of individual dipoles.Compared with fi tting-based methods,our algorithm demonstrated ultrafast speed and higher accuracy,reduced sensitivity to defocusing,strong robustness and adaptability,making it an optimal choice for both two-dimensional and threedimensional super-resolution imaging analysis.
Rational protein design is a powerful strategy,not only for revealing the structure and function relationship of natural metalloproteins,but also for creating artificial metalloproteins with improved properties and functions.Myoglobin(Mb),a small heme protein created by nature with diverse functions,has been shown to be an ideal scaffold for rational protein design.The progress reviewed herein includes fine-tuning its native functions of O2binding and transport,peroxidase activity and nitrite reductase(NIR)activity,and rational expanding its functionalities to peroxygenase,heme-copper oxidase(HCO),nitric oxide reductase(NOR),as well as hydroxylamine reductase.These studies have enhanced our understanding of how metalloproteins work in nature,and provided insights for rational design of functional metalloproteins for practical applications in the future.
The molecular mechanisms by which dense core vesicles(DCVs) translocate,tether,dock and prime are poorly understood.In this study,Caenorhabditis elegans was used as a model organism to study the function of Rab proteins and their effectors in DCV exocytosis.RAB-27/AEX-6,but not RAB-3,was found to be required for peptide release from neurons.By analyzing the movement of DCVs approaching the plasma membrane using total internal reflection fluorescence microscopy,we demonstrated that RAB-27/AEX-6 is involved in the tethering of DCVs and that its effector rabphilin/RBF-1 is required for the initial tethering and subsequent stabilization by docking.
FENG Wan JuanLIANG TaoYU JunWeiZHOU WeiZHANG YongDengWU ZhengXingXU Tao
