Acts as an inhibitor of the small GTPase RHOA and plays several roles in the regulation of myoblast and hair cell differentiation, lymphocyte T proliferation and neutrophil polarization. Plays a role in fetal mononuclear myoblast differentiation by promoting filopodia and myotube formation (By similarity). Maintains naive T lymphocytes in a quiescent state and prevents chemokine-induced T lymphocyte responses, such as cell adhesion, polarization and migration (By similarity). Involved also in the regulation of neutrophil polarization, chemotaxis and adhesion. Required for normal development of inner and outer hair cell stereocilia within the cochlea of the inner ear. Plays a role for maintaining the structural organization of the basal domain of stereocilia. Involved in mechanosensory hair cell function. Required for normal hearing (By similarity). Homooligomer; homooligomerization is regulated by RHOC and leads to the formation of concatemers through the association of N- and C-termini (By similarity). Interacts (phosphorylated form) with 14-3-3 proteins; these interactions occur during myogenic cell differentiation and also induces T cell proliferation arrest (By similarity). Interacts (phosphorylated form) with HDAC6; this interaction occurs during early myogenic differentiation, prevents HDAC6 to deacetylate tubulin and also induces T cell proliferation arrest (By similarity). Interacts with DYSF; this interaction occurs during early myogenic differentiation (By similarity). Interacts with MYOF (By similarity). Interacts (via active GTP- or inactive GDP-bound forms) with RHOA; this interaction is direct, blocks the loading of GTP to RHOA and decreases upon chemokine CCL19 stimulation in primary T lymphocytes. Interacts with RHOC (By similarity). Interacts (via phosphorylated form) with YWHAB; this interaction occurs in a chemokine-dependent manner and does not compete for binding of RIPOR2 with RHOA nor blocks inhibition of RIPOR2-mediated RHOA activity (By similarity). Interacts with YWHAE (By similarity). Interacts with YWHAQ (By similarity). Localized in the cytoplasm in cells undergoing mitosis (By similarity). Colocalized with F-actin. Accumulates at the leading edge of polarized neutrophils in a chemokine-dependent manner. Localized with RHOC within the basal domain of hair cell stereocilia, near the taper region. Detected in punctate pattern forming a circumferential ring at the stereocilia base (By similarity). Localized to the apical stereocilia of inner and outer hair cells (PubMed:24958875). Expressed in the cochlea (at protein level). Phosphorylated. Chemokine-induced phosphorylation in neutrophils occurs in a PKC- and AKT-dependent manner, resulting in RIPOR2 interaction with YWHAB and stabilization. Phosphorylated by PKCA, AKT1 and MAPKAPK1A; in vitro. Belongs to the RIPOR family.