RIPOR2

This gene encodes an atypical inhibitor of the small G protein RhoA. Inhibition of RhoA activity by the encoded protein mediates myoblast fusion and polarization of T cells and neutrophils. The encoded protein is a component of hair cell stereocilia that is essential for hearing. A splice site mutation in this gene results in hearing loss in human patients. [provided by RefSeq, Sep 2016]

RHO Family Interacting Cell Polarization Regulator 2

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 (PubMed:17150207, PubMed:24687993, PubMed:23241886, PubMed:24958875, PubMed:25588844, PubMed:27556504).
Inhibits chemokine-induced T lymphocyte responses, such as cell adhesion, polarization and migration (PubMed:23241886).
Involved also in the regulation of neutrophil polarization, chemotaxis and adhesion (By similarity).
Required for normal development of inner and outer hair cell stereocilia within the cochlea of the inner ear (By similarity).
Plays a role for maintaining the structural organization of the basal domain of stereocilia (By similarity).
Involved in mechanosensory hair cell function (By similarity).
Required for normal hearing (PubMed:24958875).
Isoform 2
Acts as an inhibitor of the small GTPase RHOA (PubMed:25588844).
Plays a role in fetal mononuclear myoblast differentiation by promoting filopodia and myotube formation (PubMed:17150207).
Maintains naive T lymphocytes in a quiescent state (PubMed:27556504).

Biological Process cell adhesionIEA:UniProtKB-KW
Biological Process cellular response to chemokineManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process chemotaxisIEA:UniProtKB-KW
Biological Process negative regulation of cell adhesionManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process negative regulation of establishment of T cell polarityManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process negative regulation of protein localization to cell leading edgeISS:UniProtKB
Biological Process negative regulation of Rho guanyl-nucleotide exchange factor activityManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process negative regulation of Rho protein signal transductionManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process negative regulation of T cell migrationManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process negative regulation of T cell proliferationIMP:UniProtKB
Biological Process positive regulation of filopodium assemblyManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process positive regulation of myoblast differentiationManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process positive regulation of myoblast fusionManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process positive regulation of neutrophil chemotaxisISS:UniProtKB
Biological Process positive regulation of neutrophil extravasationISS:UniProtKB
Biological Process regulation of cell cycleIMP:UniProtKB
Biological Process regulation of establishment of cell polarityISS:UniProtKB
Biological Process regulation of mitotic spindle assemblyIMP:UniProtKB
Biological Process sensory perception of soundManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process skeletal muscle fiber developmentIEA:InterPro

Cytoplasm
Cytoplasm, cytoskeleton
Cell projection, filopodium
Cell projection, stereocilium
Cell projection, stereocilium membrane
Apical cell membrane
Localized in the cytoplasm in cells undergoing mitosis (PubMed:17150207).
Colocalized with F-actin (PubMed:17150207).
Localized with RHOC within the basal domain of hair cell stereocilia, near the taper region (By similarity).
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 (By similarity).
Not detected as a membrane-associated protein in stereocilia (By similarity).
Isoform 1
Cytoplasm
Isoform 2
Cytoplasm
Accumulates at the leading edge of polarized neutrophils in a chemokine-dependent manner (PubMed:25588844).

Deafness, autosomal recessive, 104 (DFNB104):
A form of non-syndromic sensorineural hearing loss. Sensorineural deafness results from damage to the neural receptors of the inner ear, the nerve pathways to the brain, or the area of the brain that receives sound information.

Phosphorylated. Isoform 2 is phosphorylated in T cells (PubMed:27556504).
Chemokine-induced phosphorylation of isoform 2 in neutrophils occurs in a PKC- and AKT-dependent manner, resulting in RIPOR2 interaction with YWHAB and stabilization (PubMed:25588844).
Isoform 2 is phosphorylated by PKCA, AKT1 and MAPKAPK1A; in vitro (PubMed:25588844).
Acetylated during myogenic differentiation.