SUN and KASH: New classes of proteins form BRIDGES between nuclear matrix and cytoskeleton, spanning the PNS. (perinuclear space).
- SUN proteins: embedded in INM (inner nuclear membrane). They have at least 1 transmembrane domain, with the C-terminal domain extending into PNS.
- KASH proteins: span the outer nuclear membrane (ONM).
- SUN function: SUNs C-terminal domain extends 35aas from the C-terminus. The C-terminus is in the PNS, and recruits KASH proteins and LOCALIZES them to the ONM. N-terminal of SUN interacts with the chromosome binding proteins, connecting the CHROMOSOME/chromatin to the INM
- KASH function: N-terminus of KASH on the cytoplasmic side of the ONM, so aids in binding of cytoplasmic elements. Connecting the ONM to actin and INTERMEDIATE filaments. Also migration of nuclei (both attached to and without centrosome), and ANCHORING nuclei