Nesprin

Nesprins (nuclear envelope spectrin repeat proteins are a family of proteins that are found primarily in the outer nuclear membrane, as well as other subcellular compartments. They contain a C-terminal KASH transmembrane domain and are part of the LINC complex (Linker of Nucleoskeleton and Cytoskeleton) which is a protein network that associates the nuclear envelope (the membrane surrounding the nucleus) to the cytoskeleton, outside the nucleus, and the nuclear lamina, inside the nucleus. Nesprin-1 and -2 bind to the actin filaments. Using FRAP (Fluorescence recovery after photobleaching) and FCCS (Fluorescence cross-correlation spectroscopy), it has been shown that there is a dynamic connection between nesprin-2 and actin. Nesprin-3 binds to plectin, which is bound to the intermediate filaments, while nesprin-4 interacts with kinesin-1. Nesprins (nuclear envelope spectrin repeat proteins are a family of proteins that are found primarily in the outer nuclear membrane, as well as other subcellular compartments. They contain a C-terminal KASH transmembrane domain and are part of the LINC complex (Linker of Nucleoskeleton and Cytoskeleton) which is a protein network that associates the nuclear envelope (the membrane surrounding the nucleus) to the cytoskeleton, outside the nucleus, and the nuclear lamina, inside the nucleus. Nesprin-1 and -2 bind to the actin filaments. Using FRAP (Fluorescence recovery after photobleaching) and FCCS (Fluorescence cross-correlation spectroscopy), it has been shown that there is a dynamic connection between nesprin-2 and actin. Nesprin-3 binds to plectin, which is bound to the intermediate filaments, while nesprin-4 interacts with kinesin-1. Nesprin mediated connections to the cytoskeleton provides mechanosensory functions in cells, as the absence or disruption of Nesprin family members at the nuclear envelope interferes with the cell's ability to sense and respond to mechanical challenges. The connection between nesprin and actin stress fibers is necessary to maintain nuclear height in fibroblasts and thus may be a key regulator of nuclear mechanotransduction and gene expression program in cells.