NCBS Home page
Accession List
Pathway List
Search
Authorized Users
Help
News archives

Enter a Search String

Special character and space not allowed in the query term. Search string should be at least 2 characters long.
Search in: Search for Match By

Molecule Parameter List for PPhosphatase2A

The statistics table lists the distribution of a molecule acting either as a substrate, product, enzyme or as a molecule within the network.
The text color of a molecule is highlighted by color.
Statistics
PPhosphatase2A participated asMoleculeSum total ofEnzymeSubstrate of an enzymeProduct of an enzymeSubstrate in ReactionProduct in Reaction
No. of occurrences1040000

Accession and Pathway Details
Accession NameAccession No.Accession TypePathway Link
  • Synaptic_
    Network
  • 16Network
    Shared_Object_Synaptic_Network PKC PLA2 
    PLCbeta Gq MAPK 
    Ras EGFR Sos 
    PLC_g CaMKII CaM 
    PP1 PP2B PKA 
    AC CaRegulation 
    This model is an annotated version of the synaptic signaling network.
    The primary reference is Bhalla US and Iyengar R. Science (1999) 283(5400):381-7 but several of the model pathways have been updated.
    Bhalla US Biophys J. 2002 Aug;83(2):740-52
    Bhalla US J Comput Neurosci. 2002 Jul-Aug;13(1):49-62

    PPhosphatase2A acting as a Molecule in  
    Synaptic_Network Network
    NameAccession NamePathway NameInitial Conc.
    (uM)
    Volume
    (fL)
    Buffered
    PPhosphatase2A
  • Synaptic_
    Network

    Accession No. : 16
  • Shared_Object_
    Synaptic_
    Network

    Pathway No. : 70
  • 0.2241000No
    Refs: Pato et al Biochem J 293:35-41(93); CoInit values span a range depending on source. Pato et al 1993 Biochem J 293:35-41 and Cohen et al 1988 Meth Enz 159:390-408 estimate 80 nM from muscle Zolneierowicz et al 1994 Biochem 33:11858-11867 report levels of 0.4 uM again from muscle, but expression is also strong in brain. Our estimate of 0.224 is between these two. There are many substrates for PP2A in this model, so I put the enzyme rate calculations here: Takai&Mieskes Biochem J 275:233-239 have mol wt 36 KDa. They report Vmax of 119 umol/min/mg i.e. 125/sec for k3 for pNPP substrate, Km of 16 mM. This is obviously unreasonable for protein substrates. For chicken gizzard myosin light chan, we have Vmax = 13 umol/min/mg or about k3 = 14/sec. Pato et al 1993 Biochem J 293:35-41 report caldesmon: Km = 2.2 uM, Vmax = 0.24 umol/min/mg. They do not think caldesmon is a good substrate. Calponin: Km = 14.3, Vmax = 5. Our values approximate these.

    PPhosphatase2A acting as an Enzyme in  
    Synaptic_Network Network
     Enzyme Molecule /
    Enzyme Activity
    Accession NamePathway NameKm (uM)kcat (s^-1)RatioEnzyme TypeReagents
    1PPhosphatase2A /
    craf-deph
  • Synaptic_
    Network

    Accession No. : 16
  • Shared_Object_
    Synaptic_
    Network

    Pathway No. : 70
  • 15.656664.16667explicit E-S complexSubstrate
    craf-1*

    Product
    craf-1
        See parent PPhosphatase2A for parms
    2PPhosphatase2A /
    MAPKK-deph
  • Synaptic_
    Network

    Accession No. : 16
  • Shared_Object_
    Synaptic_
    Network

    Pathway No. : 70
  • 15.656664.16667explicit E-S complexSubstrate
    MAPKK*

    Product
    MAPKK-ser
        See: Kyriakis et al Nature 358 pp 417-421 1992 Ahn et al Curr Op Cell Biol 4:992-999 1992 for this pathway. See parent PPhosphatase2A for parms.
    3PPhosphatase2A /
    MAPKK-deph-ser
  • Synaptic_
    Network

    Accession No. : 16
  • Shared_Object_
    Synaptic_
    Network

    Pathway No. : 70
  • 15.656664.16667explicit E-S complexSubstrate
    MAPKK-ser

    Product
    MAPKK
        See parent PPhostphatase2A description for rate details
    4PPhosphatase2A /
    craf**-deph
  • Synaptic_
    Network

    Accession No. : 16
  • Shared_Object_
    Synaptic_
    Network

    Pathway No. : 70
  • 15.656664.16667explicit E-S complexSubstrate
    craf-1**

    Product
    craf-1*
        Ueki et al JBC 269(22) pp 15756-15761 1994 show hyperphosphorylation of craf, so this is there to dephosphorylate it. Identity of phosphatase is assumed to be PP2A.



    Database compilation and code copyright (C) 2022, Upinder S. Bhalla and NCBS/TIFR
    This Copyright is applied to ensure that the contents of this database remain freely available. Please see FAQ for details.