Sandbox Reserved 995: Difference between revisions

Protein Phosphatases are general class of enzymes that are responsible for dephosphorylating other molecules or proteins.  A kinase enzyme could attach a phosphate group while the phosphatases could remove the group.  The process of phosphorylation occurs in many metabolic processes and are one of the most common post transcriptional modifications.  Protein phosphatases typically use three different amino acids to phosphorylate a protein.  The three most common are serine, threonine and tyrosine.  Protein phosphatase 2A uses serine and threonine to phosphorylate a compound.  Protein Phosphatases are involved in many biological pathways.  This is due to the fact that they have broad substrate specificity.  Protein phosphatases are involved in process such as cell-cycle regulation, cell growth and cell development.  Protein phosphatases are also involved in signal transduction and can be involved with the phosphorylation of signal proteins such as Raf and MEK. The function and mechanisms of protein phosphatase is unclear to the present date.  PP2A is a three subunit holoenzyme that features a HEAT repeat, '''H'''untington-'''e'''longation-'''A''' subunit-'''T'''OR, which is also found in the  [http://en.wikipedia.org/wiki/Huntingtin/ huntingtin gene].  which codes for the amino acid glutamine. PP2A upregulates this protein sequence by an unclear mechanism. An upward excess of 35 or more CAG repeating units is the cause of the neurodegenerative disorder referred to as Huntington's Disease. <ref>PMID: 19748341</ref>