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:17873096, PubMed:24308514, PubMed:23396599, PubMed:24824484). Core component of the LINC complex which is composed of inner nuclear membrane SUN domain-containing proteins coupled to outer nuclear membrane WIP and WIT proteins. The LINC complex also involves nucleoskeletal proteins CRWN/LINC and possibly KAKU4 and the cytoskeletal myosin KAKU1. Interacts with SUN1 and SUN2 (PubMed:24667841). Binds to KAKU4 (PubMed:24824484). Recruited to the nucleus envelope (NE) by SUN proteins and is immobilised therein (PubMed:24667841). Mostly localized at the nuclear periphery and, to a lesser extent, in the nucleoplasm (PubMed:17873096). Localized on the condensing chromatin during prometaphase to anaphase, but transferred from the decondensing chromatin to the reassembling nuclear envelope during early telophase. Relocalized to the nuclear periphery during late telophase (PubMed:23396599). Expressed at low levels in roots, leaves, flowers and flower stalks. Reduced nuclear size and altered nuclear morphology. In plants lacking both CRWN1 and CRWN2, moderate dwarf and leaf-curling phenotype associated with endoreplication and strongly reduced nuclear size. Plants lacking both CRWN1 and CRWN4 exhibit slightly smaller rosettes. Plants lacking both CRWN1 and CRWN2 or both CRWN1 and CRWN3 exhibit markedly 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. Truncated N-terminus.