Component of SUN-protein-containing multivariate complexes also called LINC complexes which link the nucleoskeleton and cytoskeleton by providing versatile outer nuclear membrane attachment sites for cytoskeletal filaments (By similarity). Required for nucleus structure organization (e.g. size and shape) (PubMed:24308514, PubMed:23396599). Involved in the maintenance of interphase chromocenter integrity and organization (PubMed:24308514). Core component of the LINC complex which is composed of inner nuclear membrane SUN domain-containing proteins coupled to outer nuclear membrane WIP proteins, the nucleoskeletal CRWN/LINC proteins, and, possibly, KAKU4 (By similarity). Binds to KAKU4 (PubMed:24824484). Recruited to the nucleus envelope (NE) by SUN proteins and is immobilised therein (By similarity). Localized frequently to the nuclear periphery as punctate structures of different sizes. During prometaphase to anaphase, localized diffusely in the cytoplasm. Later assembled into punctate structures in the cytoplasm and then to the chromatin surface. Relocalized in part to the nuclear periphery during late telophase, the other part is still localized on the punctate structures (PubMed:23396599). Additional isoforms seem to exist. Expressed at low levels in roots, leaves, flowers and flower stalks. Reduced nuclear size associated with reduced chromocenter number and altered nuclear morphology. Plants lacking both CRWN1 and CRWN4 or both CRWN2 and CRWN4 exhibit slightly smaller rosettes. Plants lacking CRWN1, CRWN2 and CRWN4 or CRWN1, CRWN3 and CRWN4 are extremely stunted and set few seed. Belongs to the CRWN family. The predicted gene has been split into 2 genes: At5g65770 and At5g65780.