Probable regulator of the Hippo/SWH (Sav/Wts/Hpo) signaling pathway, a signaling pathway that plays a pivotal role in tumor suppression by restricting proliferation and promoting apoptosis. Along with NF2 can synergistically induce the phosphorylation of LATS1 and LATS2 and can probably function in the regulation of the Hippo/SWH (Sav/Wts/Hpo) signaling pathway. Acts as a transcriptional coactivator of ESR1 which plays an essential role in DYNLL1-mediated ESR1 transactivation. Regulates collagen-stimulated activation of the ERK/MAPK cascade. Modulates directional migration of podocytes. Acts as a substrate for PRKCZ and may be associated with memory performance (By similarity). Regulates collagen-stimulated activation of the ERK/MAPK cascade. Homodimer. Interacts with DDN. Interacts with DYNLL1 and histone H3. The interaction with DYNLL1 is mandatory for the recruitment and transactivation functions of ESR1 or DYNLL1 to the target chromatin and the interaction with histone H3 ensures proper regulatory interaction of WWC1-DYNLL1-ESR1 complexes with target chromatin. Interacts (via WW domains) with DDR1 (via PPxY motif) in a collagen-regulated manner. Interacts with PRKCZ (via the protein kinase domain). Forms a tripartite complex with DDR1 and PRKCZ, but predominantly in the absence of collagen. Interacts (via the ADDV motif) with PATJ (via PDZ domain 8). Interacts (via WW domains) with SYNPO (via PPxY motifs). Interacts with NF2 and SNX4 (By similarity). Colocalizes with PRKCZ in the perinuclear region. Mammary epithelium. Expressed in mammary tissue throughout development (at protein level). Strongly up-regulated during pregnancy, falls during lactation and is again up-regulated during involution of the gland at weaning. The C2-domain mediates homodimerization. Phosphorylation at Ser-542 and Ser-923 by CDK1 in response to spindle damage stress regulates mitotic exit, these two sites are dephosphorylated by CDC14B. Belongs to the WWC family. KIBRA subfamily.