Oncology & Cancer

Scientists identify new target for wide array of cancers

Many types of human cancers exhibit changes in kinase and phosphatase balances. Drugs that inhibit kinase activity have shown success in the clinic as cancer therapeutics, but the phosphatases still remain a largely underexploited ...

Oncology & Cancer

Closer to identifying leukemic stem cells

Acute myeloid leukemia is the most common type of leukemia in adults. It is characterized by the pathological expansion of immature cells (myeloblasts) that invade the bone marrow and expand into the blood, affecting the ...


Drug approved to treat tenosynovial giant cell tumor

(HealthDay)—Turalio (pexidartinib) capsules have been approved to treat adults with symptomatic tenosynovial giant cell tumor (TGCT), the U.S. Food and Drug Administration announced.

page 1 from 5


A phosphatase is an enzyme that removes a phosphate group from its substrate by hydrolysing phosphoric acid monoesters into a phosphate ion and a molecule with a free hydroxyl group (see dephosphorylation). This action is directly opposite to that of phosphorylases and kinases, which attach phosphate groups to their substrates by using energetic molecules like ATP. A common phosphatase in many organisms is alkaline phosphatase.

Protein phosphorylation is the most common and important form of reversible protein posttranslational modification (PTM), with up to 30% of all proteins being phosphorylated at any given time. Protein kinases (PKs) are the effectors of phosphorylation and catalyse the transfer of a γ-phosphate from ATP to specific amino acids on proteins. Several hundred PKs exist in mammals and are classified into distinct super-families. Proteins are phosphorylated predominantly on Ser, Thr and Tyr residues, which account for 86, 12 and 2% respectively of the phosphoproteome, at least in mammals. In contrast, protein phosphatases (PPs) are the primary effectors of dephosphorylation and can be grouped into three main classes based on sequence, structure and catalytic function. The largest class of PPs is the phosphoprotein phosphatase (PPP) family comprising PP1, PP2A, PP2B, PP4, PP5, PP6 and PP7, and the protein phosphatase Mg2+- or Mn2+-dependent (PPM) family, composed primarily of PP2C. The protein Tyr phosphatase (PTP) super-family forms the second group, and the aspartate-based protein phosphatases the third.

This text uses material from Wikipedia, licensed under CC BY-SA