Selectivity and promiscuity of the first and second PDZ domains of PSD-95 and synapse-associated protein 102.
PDZ domains typically interact with the very carboxyl terminus of their binding partners. Type 1 PDZ domains usually require valine, leucine, or isoleucine at the very COOH-terminal (P(0)) position, and serine or threonine 2 residues upstream at P(-2). We quantitatively defined the contributions of carboxyl-terminal residues to binding selectivity of the prototypic interactions of the PDZ domains of postsynaptic density protein 95 (PSD-95) and its homolog synapse-associated protein 90 (SAP102) with the NR2b subunit of the N-methyl-d-aspartate-type glutamate receptor. Our studies indicate that all of the last five residues of NR2b contribute to the binding selectivity. Prominent were a requirement for glutamate or glutamine at P(-3) and for valine at P(0) for high affinity binding and a preference for threonine over serine at P(-2), in the context of the last 11 residues of the NR2b COOH terminus. This analysis predicts a COOH-terminal (E/Q)(S/T)XV consensus sequence for the strongest binding to the first two PDZ domains of PSD-95 and SAP102. A search of the human genome sequences for proteins with a COOH-terminal (E/Q)(S/T)XV motif yielded 50 proteins, many of which have not been previously identified as PSD-95 or SAP102 binding partners. Two of these proteins, brain-specific angiogenesis inhibitor 1 and protein kinase Calpha, co-immunoprecipitated with PSD-95 and SAP102 from rat brain extracts.
Lim
Indra Adi
IA
Department of Pharmacology, University of Wisconsin, Madison, Wisconsin 53706-1532, USA.
Hall
Duane D
DD
Hell
Johannes W
JW
D000595:Amino Acid Sequence; D020533:Angiogenesis Inhibitors; D042501:Angiogenic Proteins; D000818:Animals; D016880:Anisotropy; D001921:Brain / Q000378:metabolism; D000076122:Disks Large Homolog 4 Protein; D004305:Dose-Response Relationship, Drug; D051157:Frizzled Receptors; D015894:Genome, Human; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000737:chemistry; D007700:Kinetics; D008565:Membrane Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D009479:Neuropeptides / Q000737:chemistry*; D009687:Nuclear Proteins; D010455:Peptides / Q000737:chemistry; D011233:Precipitin Tests; D011485:Protein Binding; D011493:Protein Kinase C / Q000737:chemistry; D051571:Protein Kinase C-alpha; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry; D051381:Rats; D043562:Receptors, G-Protein-Coupled; D017981:Receptors, Neurotransmitter / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013912:Threonine / Q000737:chemistry; D014157:Transcription Factors
C468226:ADGRB1 protein, human; D020533:Angiogenesis Inhibitors; D042501:Angiogenic Proteins; C116869:DLG3 protein, human; D000076122:Disks Large Homolog 4 Protein; C101195:Dlg3 protein, rat; C501449:Dlg4 protein, rat; C489742:FZD2 protein, human; D051157:Frizzled Receptors; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D009687:Nuclear Proteins; D010455:Peptides; D011506:Proteins; D043562:Receptors, G-Protein-Coupled; D017981:Receptors, Neurotransmitter; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C033652:postsynaptic density proteins; C078604:Fzd2 protein, rat; D013912:Threonine; D012694:Serine; D005982:Glutathione Transferase; C496628:PRKCA protein, human; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha