Calbindin-D28k coexpression enhances cell surface expression of Ca<SUP>2+</SUP> permeable AMPA receptors

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Other Title
  • カルビンディンＤ–２８ｋの共発現はカルシウム透過型ＡＭＰＡ受容体の細胞膜上発現を増加させる

Abstract

Recently, we reported that the expression of Ca2+ binding proteins, calbindin-D28k (CB) and parvalbumin correlates with the expression of Ca2+ permeable AMPA receptors(AMPA-Rs) in rat forebrain. We analyzed cell surface expression of a Ca2+ impermeable subunit, GluR2 and a Ca2+ permeable subunit, GluR2Q using an adenoviral-mediated expression system in COS7 cells. Biochemical measurements of cell surface expressed subunits using biotinylation experiments revealed that cell surface expression of GluR2Q is significantly increased with CB coexpression, while that of GluR2 is not. By application of AMPA-R blockers, cell surface expression of GluR2Q is increased in the absence of CB coexpression. This result suggests that the activity of AMPA-Rs formed by GluR2Q subunits suppresses cell surface expression of GluR2Q. To determine whether Ca2+ entry via Ca2+ permeable AMPA receptor causes the suppression, we used the Ca2+ chelater, BAPTA-AM. Application of BAPTA-AM increases cell surface expression of GluR2Q. These results suggest that CB enhances cell surface expression of Ca2+ permeable AMPA-Rs by buffering the increased intracellular Ca2+ that enters through Ca2+ permeable AMPA-Rs. [Jpn J Physiol 54 Suppl:S139 (2004)]

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Details 詳細情報について

  • CRID
    1390001205729907840
  • NII Article ID
    130005446929
  • DOI
    10.14849/psjproc.2004.0_s139_4
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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