| 2003 |
PTPRQ (rPTP-GMC1) has very low activity against phosphotyrosine but is active as a phosphatidylinositol phosphatase against phosphatidylinositol phosphates involved in regulation of survival, proliferation, and subcellular architecture. It can be expressed as either a transmembrane receptor-like protein or a cytosolic protein, regulated by alternative promoter use and alternative splicing. The transmembrane form localizes to the basal membrane of human podocytes. |
Enzyme activity assays, alternative promoter/splicing analysis, subcellular localization by immunolocalization in human kidney tissue and cell lines |
Experimental cell research |
High |
12837292
|
| 2013 |
The crystal structure of the PTPRQ catalytic domain was solved at 1.56 Å resolution, revealing a disordered M6 loop and flat active-site pocket that facilitates accommodation of large phosphatidylinositide substrates. Kinetic experiments demonstrated strong preference for PI(3,4,5)P3 over other PI substrates, suggesting PTPRQ downregulates Akt signalling. |
X-ray crystallography at 1.56 Å resolution, kinetic enzyme assays with phosphatidylinositide substrates |
Acta crystallographica. Section D, Biological crystallography |
High |
23897475
|
| 2009 |
Overexpression of PTPRQ (PTP-RQ) in human mesenchymal stem cells reduced differentiation into adipocytes by decreasing intracellular phosphatidylinositol phosphate levels and consequently downregulating Akt/PKB phosphorylation. |
Overexpression in human MSCs, phosphatidylinositol phosphate quantification, Western blotting for Akt/PKB phosphorylation, adipogenesis assay |
Biochemical and biophysical research communications |
Medium |
19351528
|
| 2011 |
Ptprq is a chondroitin sulfate proteoglycan associated with shaft connectors of hair bundles: chondroitinase ABC treatment caused loss of electron-dense particles at shaft connectors, increased electrophoretic mobility of Ptprq, and abolished DSD1 epitope staining in wild-type but not Ptprq-null mouse hair bundles. Multiple developmentally regulated isoforms of Ptprq are expressed on hair bundles, with isoform differences correlating with shaft connector spacing. |
Chondroitinase ABC treatment, electron microscopy, immunostaining with monoclonal antibodies (mAb 473-HD, mAb H10), comparison of wild-type vs. Ptprq(-/-) mouse inner ear |
Developmental neurobiology |
High |
20715155
|
| 2012 |
Loss of Ptprq in mice causes progressive stereocilia fusion and elongation in vestibular hair bundles (extrastriolar utricle hair bundles up to 50% longer than controls), loss of vestibular evoked potentials in the majority of mutant mice, and subtle swimming behavior defects, establishing a direct role for Ptprq in maintaining vestibular hair bundle structure and function. |
Ptprq(-/-) mouse analysis, scanning electron microscopy of hair bundles, vestibular evoked potentials, behavioral swimming tests; longitudinal study from postnatal day 5 to 12 months |
The Journal of neuroscience |
High |
22357859
|
| 2014 |
Reduction of Ptprq in the miR-96 mutant (diminuendo) mouse contributes substantially to its auditory phenotype: the morphological and electrophysiological phenotype of Ptprq-null mice resembles that of diminuendo heterozygotes, and transcriptome comparison showed broad similarity between diminuendo homozygotes and Ptprq-null mice, placing Ptprq downstream of miR-96 in the hair cell differentiation pathway. |
Microarray transcriptome analysis, scanning electron microscopy, single hair cell electrophysiology; comparison of Ptprq-null, diminuendo heterozygous, and diminuendo homozygous mice |
The European journal of neuroscience |
Medium |
24446963
|
| 2017 |
A heterozygous nonsense mutation in the last coding exon of PTPRQ (p.Trp2294*) causes autosomal dominant hearing loss (DFNA73). The mutant transcript escapes nonsense-mediated decay (NMD) in patient fibroblasts, suggesting a dominant-negative mechanism from a truncated protein lacking only six C-terminal residues. |
Next-generation sequencing, Sanger sequencing, genome-wide linkage analysis, whole-exome sequencing, semi-quantitative RT-PCR for NMD escape in patient fibroblasts |
Genetics in medicine |
Medium |
29309402
|
| 2024 |
A novel PTPRQ truncating variant (c.3697del, p.Leu1233Phefs*11) causes autosomal dominant progressive hearing loss. CRISPR-Cas9 knock-in mice heterozygous for the equivalent allele recapitulate mild progressive high-frequency hearing loss, while homozygous mice show profound hearing loss with disorganized stereocilia. Cochlear proteome analysis of homozygous mutants revealed differentially expressed pathways including oxidative phosphorylation, angiogenesis regulation, and synaptic vesicle cycling. |
CRISPR-Cas9 knock-in mouse generation, auditory brainstem response measurements, scanning electron microscopy of stereocilia, cochlear proteome analysis |
Clinical genetics |
Medium |
39434500
|
| 2025 |
Minigene assays confirmed that a deep intronic PTPRQ variant and a splice variant cause aberrant splicing, including exon skipping leading to frameshift mutations. Protein 3D structure prediction and rigid ligand docking were used to assess pathogenicity of variants escaping nonsense-mediated decay. |
Minigene splicing assays, Sanger sequencing confirmation, protein 3D structure prediction, rigid ligand docking |
BMC medical genomics |
Medium |
40165225
|
| 2025 |
Minigene assays confirmed that the PTPRQ splice variant c.6603-3 T>G causes exon 43 skipping, resulting in a frameshift mutation (p.Ser2201ArgfsTer112), establishing the molecular mechanism by which this variant disrupts PTPRQ function. |
Minigene splicing assay, Sanger sequencing, bioinformatics splicing prediction |
Journal of otology |
Medium |
41069440
|