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 MAPK

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
MAPK participated asMoleculeSum total ofEnzymeSubstrate of an enzymeProduct of an enzymeSubstrate in ReactionProduct in Reaction
No. of occurrences1001100

Accession and Pathway Details
Accession NameAccession No.Accession TypePathway Link
  • Ajay_Bhalla_
    2007_Bistable
  • 79Network
    Shared_Object_Ajay_Bhalla_2007_Bistable PKC PLA2 
    MAPK Ras CaM 
    This is a model of ERKII signaling which is bistable due to feedback. The feedback occurs through ERKII phosphorylation of phospholipase A2 (PLA2), leading to increased production of arachidonic acid (AA), which activates protein kinase C (PKC) which activates c-Raf which is upstream of ERKII.
    The model is a highly simplified variant of more detailed bistable models of MAPK signaling (Bhalla US, Iyengar R. Science. 1999 Jan 15;283(5400):381-7, Ajay SM, Bhalla US. Eur J Neurosci. 2004 Nov;20(10):2671-80)

    MAPK acting as a Molecule in  
    Ajay_Bhalla_2007_Bistable Network
    NameAccession NamePathway NameInitial Conc.
    (uM)
    Volume
    (fL)
    Buffered
    MAPK
  • Ajay_Bhalla_
    2007_Bistable

    Accession No. : 79
  • MAPK
    Pathway No. : 366
    3.6125.7No
    conc is from Sanghera et al JBC 265 pp 52 (1990) A second calculation gives 3.1 uM, from same paper. They est MAPK is 1e-4x total protein, and protein is 15% of cell wt, so MAPK is 1.5e-5g/ml = 0.36uM. which is closer to our first estimate. Lets use this. Updated 16 May 2003. Ortiz et al 1995 J Neurosci 15(2):1285-1297 provide estimates of ERK2 levels in hippocampus: 1009 ng/mg. This comes to about 3.6uM, which may still be an underestimate of synaptic levels.

    MAPK acting as a Substrate for an Enzyme in  
    Ajay_Bhalla_2007_Bistable Network
    Enzyme Molecule /
    Enzyme Activity
    Accession NamePathway NameKm (uM)kcat (s^-1)RatioEnzyme TypeReagents
    MAPKK*  /
    MAPKKtyr
  • Ajay_Bhalla_
    2007_Bistable

    Accession No. : 79
  • MAPK
    Pathway No. : 366
    0.04629680.34explicit E-S complexSubstrate
    MAPK

    Product
    MAPK-tyr
    The actual MAPKK is 2 forms from Seger et al JBC 267:20 14373(1992) Vmax = 150nmol/min/mg From Haystead et al FEBS 306(1):17-22 we get Km=46.6nM for at least one of the phosphs. Putting these together: k3=0.15/sec, scale to get k2=0.6. k1=0.75/46.6nM=2.7e-5

    MAPK acting as a Product of an Enzyme in  
    Ajay_Bhalla_2007_Bistable Network
    Enzyme Molecule /
    Enzyme Activity
    Accession NamePathway NameKm (uM)kcat (s^-1)RatioEnzyme TypeReagents
    MKP-1  /
    MKP1-tyr-deph
  • Ajay_Bhalla_
    2007_Bistable

    Accession No. : 79
  • Shared_Object_
    Ajay_Bhalla_
    2007_Bistable

    Pathway No. : 363
  • 0.13333144explicit E-S complexSubstrate
    MAPK-tyr

    Product
    MAPK
    The original kinetics have been modified to obey the k2 = 4 * k3 rule, while keeping kcat and Km fixed. As noted in the NOTES, the only constraining data point is the time course of MAPK dephosphorylation, which this model satisfies. It would be nice to have more accurate estimates of rate consts and MKP-1 levels from the literature. Effective Km : 67 nM kcat = 1.43 umol/min/mg



    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.