The presence of bestrophin-1 modulates the Ca2+ recruitment from Ca2+ stores in the ER.
Bestrophin-1, mainly analyzed in overexpression experiments, functions as Ca(2+)-dependent Cl(-) channel. Analysis of endogenously expressed bestrophin-1 suggested an influence on intracellular Ca(2+). The aim of the study is to analyze the influence of endogenously expressed bestrophin-1 on Ca(2+) homeostasis. Primary cultures of retinal pigment epithelial (RPE) cells were established from wild-type and bestrophin-1-deficient mice. Intracellular free Ca(2+) ([Ca(2+)](i)) was recorded by Ca(2+) imaging; through immunocytochemistry and differential centrifugation, subcellular localization of bestrophin-1 was analyzed. RPE cells of bestrophin-1-deficient mice showed higher levels of resting [Ca(2+)](i) than cells from wild-type mice. In cells from knockout mice and wild-type mice, ATP led to increases in [Ca(2+)](i) subsequent to phospholipase C activation. ATP-induced Ca(2+) in bestrophin-1-deficient mice rose faster and decayed slower. In cells from wild-type mice, ATP led to [Ca(2+)](i) increase via depletion of Ca(2+) from thapsigargin-sensitive stores. In cells from bestrophin-1-deficient mice, ATP-dependent increase in [Ca(2+)](i) resulted in 40% of cells from depletion of bafilomycin-sensitive and in 60% from thapsigargin-sensitive Ca(2+) stores. After differential centrifugation, bestrophin-1 was found in fractions enriched of ClC-3 Cl channel and myosin-7A. Co-localization analysis of bestrophin-1, with beta-catenin or pan-cadherin, in fresh sections of porcine retina, revealed bestrophin-1 in the basolateral membrane. A portion of endogenously expressed bestrophin-1,localized in the endoplasmic reticulum, influenced uptake of Ca(2+) into Ca(2+) stores. Therefore, bestrophin-1 possibly conducts Cl(-) as counter ion for Ca(2+) uptake into cytosolic Ca(2+) stores.
Neussert
Rudgar
R
Experimental Eye Research, Eye Hospital, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
Müller
Claudia
C
Milenkovic
Vladimir M
VM
Strauss
Olaf
O
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000075002:Bestrophins; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D002712:Chlorides / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D006706:Homeostasis; D007150:Immunohistochemistry; D007473:Ion Channels; D018942:Macrolides / Q000494:pharmacology; D051379:Mice; D018345:Mice, Knockout; D008856:Microscopy, Fluorescence; D055213:Retinal Pigment Epithelium / Q000187:drug effects / Q000378:metabolism*; D013552:Swine; D019284:Thapsigargin / Q000494:pharmacology; D013997:Time Factors; D010738:Type C Phospholipases / Q000378:metabolism
C491856:Best1 protein, mouse; D000075002:Bestrophins; D002712:Chlorides; D004791:Enzyme Inhibitors; D005136:Eye Proteins; D007473:Ion Channels; D018942:Macrolides; D019284:Thapsigargin; D000255:Adenosine Triphosphate; D010738:Type C Phospholipases; D000252:Calcium-Transporting ATPases; D002118:Calcium
Prog Retin Eye Res. 2009 May;28(3):206-26
19398034
J Cell Sci. 2006 Jan 15;119(Pt 2):226-38
16410548
Annu Rev Physiol. 2008;70:273-99
17850212
J Gen Physiol. 2004 Apr;123(4):327-40
15051805
Purinergic Signal. 2008 Jun;4(2):101-7
18368526
Exp Eye Res. 2005 Apr;80(4):465-75
15781274
J Physiol. 1999 Nov 1;520 Pt 3:745-59
10545141
Hum Mol Genet. 1998 Sep;7(9):1517-25
9700209
J Biol Chem. 1985 Mar 25;260(6):3440-50
3838314
Physiol Rev. 2008 Apr;88(2):639-72
18391176
Pflugers Arch. 2010 Feb;459(3):485-97
19823864
J Gen Physiol. 2006 May;127(5):577-89
16636205
Neurosci Lett. 2008 May 9;436(2):102-6
18358607
Biol Res. 2002;35(2):177-82
12415734
FASEB J. 2006 Jan;20(1):178-80
16282372
Nat Genet. 1998 Jul;19(3):241-7
9662395
J Physiol. 2001 Jul 1;534(Pt 1):193-202
11433002
J Neurosci. 2008 May 28;28(22):5660-70
18509027
Pflugers Arch. 2009 Jun;458(2):431-41
19130075
Physiol Rev. 2005 Jul;85(3):845-81
15987797
Proc Natl Acad Sci U S A. 2002 Mar 19;99(6):4008-13
11904445
Genome Biol. 2002 Jun 18;3(7):RESEARCH0034
12184808
J Neurosci. 1997 Apr 1;17(7):2324-37
9065493
Br J Pharmacol. 2004 Nov;143(5):525-32
15466449
Proc Natl Acad Sci U S A. 2000 Nov 7;97(23):12758-63
11050159
Exp Cell Res. 1992 Nov;203(1):192-7
1330655
J Neurosci Res. 1997 Jul 1;49(1):43-52
9211988
Am J Hum Genet. 2008 Jan;82(1):19-31
18179881
J Physiol. 2005 Jan 15;562(Pt 2):477-91
15564283
Invest Ophthalmol Vis Sci. 2002 Nov;43(11):3555-66
12407168
Trends Neurosci. 2001 May;24(5):271-6
11311379
Biochem Soc Trans. 2003 Oct;31(Pt 5):947-9
14505455
Invest Ophthalmol Vis Sci. 2008 Jan;49(1):350-7
18172112
Cell Calcium. 2003 May-Jun;33(5-6):337-44
12765680