Cytoskeletal protein required for organization of normal actin cytoskeleton. Roles in establishing cell morphology, motility, cell adhesion and cell-extracellular matrix interactions in a variety of cell types. May function as a scaffolding molecule with the potential to influence both actin polymerization and the assembly of existing actin filaments into higher-order arrays. Binds to proteins that bind to either monomeric or filamentous actin. Localizes at sites where active actin remodeling takes place, such as lamellipodia and membrane ruffles. Different isoforms may have functional differences. Involved in the control of morphological and cytoskeletal changes associated with dendritic cell maturation. Involved in targeting ACTN to specific subcellular locations. May be required for the initiation of neural tube closure. Interacts with EPS8 (PubMed:16868024). Interacts with LASP1 (PubMed:16492705). Interacts with VASP (PubMed:14983521). Interacts with ACTN (By similarity). Interacts with SORBS2 (By similarity). Interacts with PFN1 (By similarity). Interacts with LPP (By similarity). Interacts with SPIN90 (By similarity). Interacts with SRC (By similarity). Interacts with EZR (By similarity). Interacts with RAI14 (By similarity). Localizes to stress fibers and Z lines (PubMed:10931874). Preferentially expressed in the excitatory presynaptic terminals (By similarity). Detected in both muscle and non-muscle tissues and cells (at protein level). Isoform 3 is widely expressed, isoform 4 is particularly abundant in tissues rich in smooth muscle and in the cardiac muscle and isoform 1 is detected in heart. Ubiquitously detected in embryonic tissues, and down-regulated in certain adult tissues (at protein level). Isoform 3 is widely expressed in embryonic tissues (at protein level). In adults is detected in spleen and gut, and is almost undetectable in heart, skeletal muscle, liver, and kidney (at protein level). Isoform 4 is widely expressed in neonatal tissues (brain, heart, lung, stomach, intestine, kidney, bone and skin) (at protein level). Late in development expression is restricted to cardiac muscle and to organs rich in smooth muscle (at protein level). Isoform 1 is detected in neonatal striated muscle and bone, and remains highly expressed in adult skeletal and cardiac muscle (at protein level). Adult brain express an isoform of 80-85 kDa. At 8.5 dpc is mainly expressed the rostral and caudal part of neural plate. No expression is detected in somite. At 9.5 dpc and 10.5 dpc is ubiquitously detected. Phosphorylated predominantly on serines and, to a lesser extent, on tyrosines. Phosphorylation at Ser-1143 by PKB/AKT1 modulates cytoskeletal organization and cell motility (By similarity). Death around 15.5 dpc due to severe neural tube closure defects and herniation of liver and intestine. Palld-deficient mouse embryonic fibroblasts display disorganized actin cytoskeleton, decreased polymerized filament actin, and decreased cell adhesion and compromised cell spreading on various extracellular matrix. Mice embryos lacking Palld exhibit defects in erythropoiesis. Belongs to the myotilin/palladin family.