PSD-95 mediates membrane clustering of the human plasma membrane Ca2+ pump isoform 4b

Rita Padányi, Katalin Pászty, Emanuel E. Strehler, Ágnes Enyedi

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


Besides the control of global calcium changes, specific plasma membrane calcium ATPase (PMCA) isoforms are involved in the regulation of local calcium signals. Although local calcium signaling requires the confinement of signaling molecules into microdomains, little is known about the specific organization of PMCA molecules within the plasma membrane. Here we show that co-expression with the postsynaptic density-95 (PSD-95) scaffolding protein increased the plasma membrane expression of PMCA4b and redistributed the pump into clusters. The clustering of PMCA4b was fully dependent on the presence of its PDZ-binding sequence. Using the fluorescence recovery after photobleaching (FRAP) technique, we show that the lateral membrane mobility of the clustered PMCA4b is significantly lower than that of the non-clustered molecules. Disruption of the actin-based cytoskeleton by cytochalasin D resulted in increased cluster size. Our results suggest that PSD-95 promotes the formation of high-density PMCA4b microdomains in the plasma membrane and that the membrane cytoskeleton plays an important role in the regulation of this process.

Original languageEnglish (US)
Pages (from-to)1023-1032
Number of pages10
JournalBiochimica et Biophysica Acta - Molecular Cell Research
Issue number6
StatePublished - Jun 2009


  • Calcium pump
  • FRAP
  • Membrane clustering
  • PDZ protein
  • PSD-95
  • Plasma membrane Ca ATPase

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology


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