Alternative titles; symbolsPROTEIN TYROSINE PHOSPHATASE, NONRECEPTOR-TYPE, 20A; PTPN20AHGNC Approved Gene Symbol: PTPN20Cytogenetic location: 10q11.22 Genomi...
Alternative titles; symbols
HGNC Approved Gene Symbol: PTPN20
Cytogenetic location: 10q11.22 Genomic coordinates (GRCh38): 10:46,911,371-47,003,828 (from NCBI)
Protein tyrosine phosphorylation plays an integral role in cellular signaling and controls diverse cellular responses. Tyrosine phosphorylation is a reversible and dynamic process controlled by the activities of protein tyrosine kinases, which mediate the phosphorylation reaction, and protein tyrosine phosphatases, such as PTPN20, which catalyze tyrosine dephosphorylation (Fodero-Tavoletti et al., 2005).
▼ Cloning and Expression
Using differential display to identify genes upregulated during differentiation in human umbilical vein endothelial cells, followed by 5-prime RACE of human testis and umbilical vein endothelial cell mRNA, Fodero-Tavoletti et al. (2005) cloned multiple PTPN20 splice variants. The most widely expressed variant encodes a deduced 411-amino acid protein with a 280-amino acid PTP catalytic domain containing 10 conserved catalytic motifs. Northern blot analysis detected high expression of a 3.0-kb PTPN20 transcript in testis. RT-PCR detected the primary PTPN20 transcript in all human cell lines examined, whereas the other variants showed more restricted and variable expression. Western blot analysis detected PTPN20 at an apparent molecular mass of 47.4 kD. In nonsynchronized transfected COS-1 cells, epitope-tagged PTPN20 showed an endoplasmic reticulum (ER) and Golgi localization in some cells, and diffuse cytoplasmic and cell peripheral staining in others.
▼ Gene Function
By in vitro analysis, Fodero-Tavoletti et al. (2005) found that recombinant PTPN20 exhibited catalytic activity toward tyrosyl-phosphorylated substrates. In serum-starved COS-1 cells, PTPN20 was targeted to the nucleus and the microtubule network, colocalizing with the microtubule-organizing center and intracellular membrane compartments, including the ER and Golgi apparatus. Stimulation of cells with EGF (131530), osmotic shock, a PTP inhibitor, or integrin ligation targeted PTPN20 to actin-rich structures that included membrane ruffles.
▼ Gene Structure
Fodero-Tavoletti et al. (2005) determined that the PTPN20 gene contains 12 exons and spans 92 kb.
By genomic sequence analysis and FISH, Fodero-Tavoletti et al. (2005) mapped the PTPN20 gene to chromosome 10q11.2. They identified a putative PTPN20 pseudogene approximately 500 kb downstream of PTPN20.