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 CaMKII

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
CaMKII participated asMoleculeSum total ofEnzymeSubstrate of an enzymeProduct of an enzymeSubstrate in ReactionProduct in Reaction
No. of occurrences1000220

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

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

    Accession No. : 16
  • CaMKII
    Pathway No. : 80
    701000No
    Huge concentration of CaMKII. In PSD it is 20-40% of protein, so we assume it is around 2.5% of protein in spine as a whole. This level is so high it is unlikely to matter much if we are off a bit. This comes to about 70 uM. Seen the review: Hanson and Schulman 1992 Ann. Rev. Biuochem 60:559-601

    CaMKII acting as a Product of an Enzyme in  
    Synaptic_Network Network
     Enzyme Molecule /
    Enzyme Activity
    Accession NamePathway NameKm (uM)kcat (s^-1)RatioEnzyme TypeReagents
    1PP1-active  /
    Deph-thr306
  • Synaptic_
    Network

    Accession No. : 16
  • Shared_Object_
    Synaptic_
    Network

    Pathway No. : 70
  • 5.099070.354explicit E-S complexSubstrate
    CaMK-thr306

    Product
    CaMKII
        Dephosphorylation kinetics are assumed to be the same for all phosphorylation sites on CaMKII. The rates are from Stralfors et al Eur J Biochem 149 295-303 giving Vmax = 5.7 umol/min giving k3 = 3.5/sec and k2 = 14. Foulkes et al Eur J Biochem 132 309-313 1983 give Km = 5.1 uM so k1 becomes 5.72e-6 Simonelli 1984 (Grad Thesis, CUNY) showed that other substrates are about 1/10 rate of phosphorylase a, so we reduce k1,k2,k3 by 10 to 5.72e-7, 1.4, 0.35. This gives the final Km of 5.1, and Vmax of 0.35/sec.
    2PP1-active  /
    Deph_thr286b
  • Synaptic_
    Network

    Accession No. : 16
  • Shared_Object_
    Synaptic_
    Network

    Pathway No. : 70
  • 5.099070.354explicit E-S complexSubstrate
    CaMKII-thr286

    Product
    CaMKII
        Rates are assumed to be the same for all phosphorylation sites on CaMKII. The rates are from Stralfors et al Eur J Biochem 149 295-303 giving Vmax = 5.7 umol/min giving k3 = 3.5/sec and k2 = 14. Foulkes et al Eur J Biochem 132 309-313 1983 give Km = 5.1 uM so k1 becomes 5.72e-6 Simonelli 1984 (Grad Thesis, CUNY) showed that other substrates are about 1/10 rate of phosphorylase a, so we reduce k1,k2,k3 by 10 to 5.72e-7, 1.4, 0.35. This gives the final Km of 5.1, and Vmax of 0.35/sec.

    CaMKII acting as a Substrate in a reaction in  
    Synaptic_Network Network
    Kd is calculated only for second order reactions, like nA+nB <->nC or nA<->nC+nD, where n is number and A,B,C,D are molecules, where as for first order reactions Keq is calculated. Kd for higher order reaction are not consider.
     NameAccession NamePathway NameKfKbKdtauReagents
    1CaMKII-bind-CaM
  • Synaptic_
    Network

    Accession No. : 16
  • CaMKII
    Pathway No. : 80
    49.9998
    (uM^-1 s^-1)
    5
    (s^-1)
    Kd(bf) = 0.1(uM)-Substrate
    CaM-Ca4
    CaMKII

    Product
    CaMKII-CaM
      This is tricky. There is some cooperativity here arising from interactions between the subunits of the CAMKII holoenzyme. However, the stoichiometry is 1. Kd = 0.1 uM. Rate is fast (see Hanson et al Neuron 12 943-956 1994) Hanson and Schulman 1992 AnnRev Biochem 61:559-601 give tau for dissoc as 0.2 sec at low Ca, 0.4 at high. Low Ca = 100 nM = physiol.
    2basal-activity
  • Synaptic_
    Network

    Accession No. : 16
  • CaMKII
    Pathway No. : 80
    0.003
    (s^-1)
    0
    (s^-1)
    --Substrate
    CaMKII

    Product
    CaMKII-thr286
      This reaction represents one of the unknowns in CaMK-II biochemistry: what maintains the basal level of phosphorylation on thr 286 ? See Hanson and Schulman Ann Rev Biochem 1992 61:559-601, specially pg 580, for review. I have not been able to find any compelling mechanism in the literature, but fortunately the level of basal activity is well documented. Lisman et al propose that the levels of PP1 are very low in the postsynaptic density, and PP2A is excluded from the PSD, and this would lead to autophosphorylation at a sustained level.



    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.