Ultrahigh-resolution stimulation by femtosecond laser reveals existence and regulation mechanism of nuclear Ca~(2+) store

摘要

Nuclear Ca~(2+) regulates many signaling pathways including NFAT, CREB, MEF that are essential to cell immunity,development and differentiation. In current stage, there is no specified biochemical drugs to regulate nuclear Ca~(2+)individually. The existence of nuclear Ca~(2+) store remains unknown. In this study, we show the femtosecond-laserstimulation can precisely regulate nuclear and other subcellular Ca~(2+) stores exclusively. The stimulated Ca~(2+) store can bereleased but other subcellular Ca~(2+) stores are not interfered by femtosecond laser. By using this method, we present theevidence of the endogenous Ca~(2+) store inside nucleus. The nuclear Ca~(2+) store volume and release mechanism areclarified. By photostimulation, nuclear Ca~(2+) store can be released and impact the calcium in endoplasmic reticulum (ER),suggesting a Ca~(2+) transmission channel between nucleus and ER. The permeability of nuclear pore complex (NPC) toCa~(2+) at different Ca~(2+) levels is also found different. This study indicates the existence of nuclear Ca~(2+) store and the finalmapping of subcellular Ca~(2+) stores. This result thus is of great significance to the cell calcium theory, Ca~(2+) signaling,Ca~(2+)-related cell processes, and further other Ca~(2+)-related fields.