Functions as a molecular adapter coordinating multiple protein-protein interactions at the focal adhesion complex and in the nucleus. Links various intracellular signaling modules to plasma membrane receptors and regulates the Wnt and TGFB signaling pathways. May also regulate SLC6A3 and SLC6A4 targeting to the plasma membrane hence regulating their activity. In the nucleus, functions as a nuclear receptor coactivator regulating glucocorticoid, androgen, mineralocorticoid and progesterone receptor transcriptional activity. May play a role in the processes of cell growth, proliferation, migration, differentiation and senescence. May have a zinc-dependent DNA-binding activity. Homooligomer. Interacts with CRIP2, HSPB1, ILK, LIMS1, LIMS2, NCK2, NUDT16L1, PAK, PPARG, PTPN12, TCF3, TCF7L2 and VCL. Forms a complex with GIT1 and ARHGEF7. Interacts with AR/androgen receptor in a ligand-dependent manner. Interacts with CSK, LYN, MAPK15, NR3C1, PPARG, PTK2/FAK1, PTK2B/PYK2, SLC6A3, SLC6A4, SMAD3, SRC and talin. Interacts (via LIM zinc-binding domain 2) with CBLC (via RING-type zinc finger); the interaction is direct and enhances CBLC E3 ubiquitin-protein ligase activity (By similarity). Associated with the actin cytoskeleton, colocalizes with stress fibers. The LIM zinc-binding domains mediate glucocorticoid receptor coactivation and interaction with AR, CRIP2, ILK, LIMS1, NR3C1, PPARG, TCF3, TCF7L2, SLC6A3 and SMAD3. The LIM zinc-binding 2 and LIM zinc-binding 3 domains mediate targeting to focal adhesions and actin stress fibers. The LIM zinc-binding 3 and LIM zinc-binding 4 domains mediate interaction with TRAF4 and MAPK15. The LIM zinc-binding 4 domain mediates interaction with HSPB1, homooligomerization and targeting to the nuclear matrix. The LIM zinc-binding 3 domain mediates interaction with PTPN12 (By similarity). The LD (leucine and aspartate-rich) motif 3 mediates interaction with GIT1 and functions as a nuclear export signal. Phosphorylated by gonadotropin-releasing hormone-activated SRC. Belongs to the paxillin family. Truncated N-terminus.