title: Plasma membrane associated membranes (PAM) from Jurkat cells contain STIM1 protein is PAM involved in the capacitative calcium entry?
abstract: A proper cooperation between the plasma membrane, the endoplasmic reticulum and the mitochondria seems to be essential for numerous cellular processes involved in Ca(2+) signalling and maintenance of Ca(2+) homeostasis. A presence of microsomal and mitochondrial proteins together with those characteristic for the plasma membrane in the fraction of the plasma membrane associated membranes (PAM) indicates a formation of stabile interactions between these three structures. We isolated the plasma membrane associated membranes from Jurkat cells and found its significant enrichment in the plasma membrane markers including plasma membrane Ca(2+)-ATPase, Na(+), K(+)-ATPase and CD3 as well as sarco/endoplasmic reticulum Ca(2+) ATPase as a marker of the endoplasmic reticulum membranes. In addition, two proteins involved in the store-operated Ca(2+) entry, Orai1 located in the plasma membrane and an endoplasmic reticulum protein STIM1 were found in this fraction. Furthermore, we observed a rearrangement of STIM1-containing protein complexes isolated from Jurkat cells undergoing stimulation by thapsigargin. We suggest that the inter-membrane compartment composed of the plasma membrane and the endoplasmic reticulum, and isolated as a stabile plasma membrane associated membranes fraction, might be involved in the store-operated Ca(2+) entry, and their formation and rebuilding have an important regulatory role in cellular Ca(2+) homeostasis.
authors.affiliation: Department of Biochemistry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteur Street 3, 02-093 Warsaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kozieł
authors.forename: Magdalena
authors.initials: M
authors.lastname: Lebiedzinska
authors.forename: Gyorgy
authors.initials: G
authors.lastname: Szabadkai
authors.forename: Marta
authors.initials: M
authors.lastname: Onopiuk
authors.forename: Wojciech
authors.initials: W
authors.lastname: Brutkowski
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Wierzbicka
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Wilczyński
authors.forename: Paolo
authors.initials: P
authors.lastname: Pinton
authors.forename: Jerzy
authors.initials: J
authors.lastname: Duszyński
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Zabłocki
authors.forename: Mariusz R
authors.initials: MR
authors.lastname: Wieckowski
mesh_terms: D001693:Biological Transport, Active / Q000187:drug effects / Q000276:immunology; D017252:CD3 Complex / Q000378:metabolism; D002118:Calcium / Q000276:immunology / Q000378:metabolism*; D015220:Calcium Channels / Q000276:immunology / Q000378:metabolism; D020013:Calcium Signaling; D002458:Cell Fractionation; D002462:Cell Membrane / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000276:immunology / Q000378:metabolism*; D000071740:ORAI1 Protein; D053499:Plasma Membrane Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D000071737:Stromal Interaction Molecule 1; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D017252:CD3 Complex; D015220:Calcium Channels; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1; D019284:Thapsigargin; D053499:Plasma Membrane Calcium-Transporting ATPases; D002118:Calcium