Plasma membrane Ca2+-atpase isoforms 2b and 4b interact promiscuously and selectively with members of the membrane-associated guanylate kinase family of PDZ (PSD95/Dlg/ZO-1) domain-containing proteins.
Spatial and temporal regulation of intracellular Ca(2+) signaling depends on localized Ca(2+) microdomains containing the requisite molecular components for Ca(2+) influx, efflux, and signal transmission. Plasma membrane Ca(2+)-ATPase (PMCA) isoforms of the "b" splice type contain predicted PDZ (PSD95/Dlg/ZO-1) interaction domains. The COOH-terminal tail of PMCA2b isolated the membrane-associated guanylate kinase (MAGUK) protein SAP97/hDlg as a binding partner in a yeast two-hybrid screen. The related MAGUKs SAP90/PSD95, PSD93/chapsyn-110, SAP97, and SAP102 all bound to the COOH-terminal tail of PMCA4b, whereas only the first three bound to the tail of PMCA2b. Coimmunoprecipitations confirmed the interaction selectivity between PMCA4b and SAP102 as opposed to the promiscuity of PMCA2b and 4b in interacting with other SAPs. Confocal immunofluorescence microscopy revealed the exclusive presence and colocalization of PMCA4b and SAP97 in the basolateral membrane of polarized Madin-Darby canine kidney epithelial cells. In hippocampal neurons, PMCA2b was abundant throughout the somatodendritic compartment and often extended into the neck and head of individual spines where it colocalized with SAP90/PSD95. These data show that PMCA "b" splice forms interact promiscuously but also with specificity with different members of the PSD95 family of SAPs. PMCA-SAP interactions may play a role in the recruitment and maintenance of the PMCA at specific membrane domains involved in local Ca(2+) regulation.
DeMarco
S J
SJ
Program in Molecular Neuroscience, Department of Biochemistry, Mayo Graduate School, Mayo Clinic, Rochester, Minnesota 55905, USA.
Strehler
E E
EE
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D019556:COS Cells; D020013:Calcium Signaling / Q000502:physiology*; D000252:Calcium-Transporting ATPases / Q000737:chemistry* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D000076122:Disks Large Homolog 4 Protein; D004926:Escherichia coli; D051528:Guanylate Kinases; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D009703:Nucleoside-Phosphate Kinase / Q000737:chemistry / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D025521:Tumor Suppressor Proteins; D062826:Zonula Occludens-1 Protein
C501444:DLG4 protein, human; D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; C501451:Mpp2 protein, rat; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D011994:Recombinant Proteins; C569042:TJP1 protein, human; C569044:Tjp1 protein, rat; D025521:Tumor Suppressor Proteins; D062826:Zonula Occludens-1 Protein; C033652:postsynaptic density proteins; D009703:Nucleoside-Phosphate Kinase; C496468:DLG2 protein, human; D051528:Guanylate Kinases; D000252:Calcium-Transporting ATPases