The function of LUZP1 (leucine zipper protein 1, ENSG00000169641) is as follows. F-actin cross-linking protein (PubMed:30990684). Stabilizes actin and acts as a negative regulator of primary cilium formation (PubMed:32496561). Positively regulates the phosphorylation of both myosin II and protein phosphatase 1 regulatory subunit PPP1R12A/MYPT1 and promotes the assembly of myosin II stacks within actin stress fibers (PubMed:38832964). Inhibits the phosphorylation of myosin light chain MYL9 by DAPK3 and suppresses the constriction velocity of the contractile ring during cytokinesis (PubMed:38009294). Binds to microtubules and promotes epithelial cell apical constriction by up- regulating levels of diphosphorylated myosin light chain (MLC) through microtubule-dependent inhibition of MLC dephosphorylation by myosin phosphatase (By similarity). Involved in regulation of cell migration, nuclear size and centriole number, probably through regulation of the actin cytoskeleton (By similarity). Component of the CERF-1 and CERF-5 chromatin remodeling complexes in embryonic stem cells where it acts to stabilize the complexes (By similarity). Plays a role in embryonic brain and cardiovascular development (By similarity). {ECO:0000250|UniProtKB:Q8R4U7, ECO:0000269|PubMed:30990684, ECO:0000269|PubMed:32496561, ECO:0000269|PubMed:38009294, ECO:0000269|PubMed:38832964}.