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Rodent Osteoblastic Cells Express Voltage-Sensitive Calcium Channels Lacking a γ Subunit

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Abstract

Voltage-sensitive calcium channels (VSCC) open in response to external stimuli, including calcitropic hormones, that alter plasma membrane calcium (Ca2+) permeability. Ca2+ that enters the cell through these channels serves a second messenger function, eliciting cellular responses that include secretion and changes in gene expression. In osteoblasts, VSCCs serve as key regulators of Ca2+ permeability and are a major class of calcitropic hormone-sensitive Ca2+ channels present in the plasma membrane. The members of the VSCC family exist as a complex of polypeptide subunits that are comprised of a pore-forming α1 subunit, an intracellular β subunit, a dimer of disulfide-linked α2 and δ subunits, and in some tissues, a γ subunit. Previous studies in our laboratory have shown that the major functional α1 subunit present in osteoblasts is the α1C (CaV1.2). To determine the complement of auxiliary subunits present in rodent osteoblastic cells, we employed RT-PCR using a battery of subunit specific primers and appropriate tissue controls. Immunohistochemistry also was performed, using available subunit specific antibodies, to measure protein expression and localization. Cell types examined included MC3T3-E1 at various stages of differentiation, ROS 17/2.8 osteosarcoma, and primary cultures of rat calvarial osteoblasts. The results indicate that all cells expressed multiple β subunit classes and α2δ dimers, but no γ subunits, regardless of differentiation state. We propose a structure for the functional osteoblast VSCC that consists of α1, β, α2δ subunits and is devoid of a γ subunit.

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References

  1. GR Mundy (1999) ArticleTitleCellular and molecular regulation of bone turnover. Bone (suppl) 24 35S–38S Occurrence Handle10.1016/S8756-3282(99)00044-7 Occurrence Handle1:STN:280:DyaK1M3ltlynsw%3D%3D

    Article  CAS  Google Scholar 

  2. MC de Vernejoul (1996) ArticleTitleDynamics of bone remodelling: biochemical and pathophysiological basis. Eur J Clin Chem Clin Biochem 34 IssueID9 729–734 Occurrence Handle1:CAS:528:DyaK28XmtFKqsbY%3D Occurrence Handle8891525

    CAS  PubMed  Google Scholar 

  3. JM Caffrey MC Farach-Carson (1989) ArticleTitleVitamin D3 metabolites modulate dihydropyridine-sensitive calcium currents in clonal rat osteosarcoma cells. J Biol Chem 264 IssueID34 20265–20274 Occurrence Handle1:CAS:528:DyaL1MXmtlWisb0%3D Occurrence Handle2479647

    CAS  PubMed  Google Scholar 

  4. D Chesnoy-Marchais J Fritsch (1998) ArticleTitleVoltage-gated sodium and calcium currents in rat osteoblasts. J Physiol 398 291–311

    Google Scholar 

  5. R Civitelli et al. (1990) ArticleTitleNongenomic activation of the calcium message system by vitamin D metabolites in osteoblast-like cells. Endocrinology 127 IssueID5 2253–2262 Occurrence Handle1:CAS:528:DyaK3cXmt1GitLc%3D Occurrence Handle2226314

    CAS  PubMed  Google Scholar 

  6. RL Duncan CH Turner (1995) ArticleTitleMechanotransduction and the functional response of bone to mechanical strain. Calcif Tissue Int 57 IssueID5 344–358 Occurrence Handle1:CAS:528:DyaK2MXovVart7o%3D Occurrence Handle8564797

    CAS  PubMed  Google Scholar 

  7. M Lieberherr (1987) ArticleTitleEffects of vitamin D3 metabolites on cytosolic free calcium in confluent mouse osteobasts. J Biol Chem 262 IssueID27 13168–13173 Occurrence Handle1:CAS:528:DyaL2sXlvFWktrw%3D Occurrence Handle3477543

    CAS  PubMed  Google Scholar 

  8. A Miyauchi et al. (2000) ArticleTitleParathyroid hormone-activated volume-sensitive calcium influx pathways in mechanically loaded osteocytes. J Biol Chem 275 IssueID5 3335–4233 Occurrence Handle10.1074/jbc.275.5.3335 Occurrence Handle1:CAS:528:DC%2BD3cXhtVygsbw%3D Occurrence Handle10652322

    Article  CAS  PubMed  Google Scholar 

  9. J You et al. (2001) ArticleTitleOsteopontin gene regulation by oscillatory fluid flow via intracellular calcium mobilization and activation of mitogen-activated protein kinase in MC3T3-E1 osteoblasts. J Biol Chem 276 IssueID16 13365–13371 Occurrence Handle10.1074/jbc.M009846200 Occurrence Handle1:CAS:528:DC%2BD3MXjtFymt7w%3D Occurrence Handle11278573

    Article  CAS  PubMed  Google Scholar 

  10. J Duriez et al. (1993) ArticleTitleEffects of the calcium channel blocker nifedipine on epiphyseal growth plate and bone turnover: a study in rabbit. Calcif Tissue Int 52 IssueID2 120–124 Occurrence Handle1:CAS:528:DyaK3sXhvVejurY%3D Occurrence Handle8443687

    CAS  PubMed  Google Scholar 

  11. W Li MC Farach-Carson (2001) ArticleTitleParathyroid hormone-stimulated resorption in calvaria cultured in serum-free medium is enhanced by the calcium-mobilizing activity of 1,25-dihydroxyvitamin D3. Bone 29 IssueID3 231–235 Occurrence Handle10.1016/S8756-3282(01)00572-5 Occurrence Handle1:CAS:528:DC%2BD3MXms12ksbk%3D Occurrence Handle11557366

    Article  CAS  PubMed  Google Scholar 

  12. WA Catterall (1995) ArticleTitleStructure and function of voltage-gated ion channels. Annu Rev Biochem 64 493–531 Occurrence Handle1:CAS:528:DyaK2MXmsl2qsbc%3D Occurrence Handle7574491

    CAS  PubMed  Google Scholar 

  13. WA Catterall (2000) ArticleTitleStructure and regulation of voltage-gated Ca2+ channels. Annu Rev Cell Dev Biol 16 521–555 Occurrence Handle1:CAS:528:DC%2BD3MXpvFyr Occurrence Handle11031246

    CAS  PubMed  Google Scholar 

  14. RW Tsien RY Tsien (1990) ArticleTitleCalcium channels, stores, and oscillations. Annu Rev Cell Biol 6 715–760 Occurrence Handle1:CAS:528:DyaK3MXitVCjurk%3D Occurrence Handle2177344

    CAS  PubMed  Google Scholar 

  15. MK Ahlijanian RE Westenbroek WA Catterall (1990) ArticleTitleSubunit structure and localization of dihydropyridine-sensitive calcium channels in mammalian brain, spinal cord, and retina. Neuron 4 IssueID6 819–832 Occurrence Handle1:CAS:528:DyaK3cXltFars78%3D Occurrence Handle2163262

    CAS  PubMed  Google Scholar 

  16. KS De Jongh C Warner WA Catterall (1990) ArticleTitleSubunits of purified calcium channels. α 2 and δ are encoded by the same gene. J Biol Chem 265 IssueID25 14738–14741 Occurrence Handle1:CAS:528:DyaK3cXmtVKqtbs%3D Occurrence Handle2168391

    CAS  PubMed  Google Scholar 

  17. N Klugbauer et al. (1999) ArticleTitleMolecular diversity of the calcium channel α2δ subunit. J Neurosci 19 IssueID2 684–691 Occurrence Handle1:CAS:528:DyaK1MXltlanuw%3D%3D Occurrence Handle9880589

    CAS  PubMed  Google Scholar 

  18. G Varadi et al. (1999) ArticleTitleMolecular elements of ion permeation and selectivity within calcium channels. Crit Rev Biochem Mol Biol 34 IssueID3 181–214 Occurrence Handle1:CAS:528:DyaK1MXksFGmsr8%3D Occurrence Handle10473347

    CAS  PubMed  Google Scholar 

  19. S Kadiyala et al. (2001) ArticleTitleMetabolites and analogs of 1α,25-dihydroxyvitamin D3: evaluation of actions in bone. Steroids 66 IssueID3-5 347–355 Occurrence Handle10.1016/S0039-128X(00)00167-7 Occurrence Handle1:CAS:528:DC%2BD3MXhtFeht7w%3D Occurrence Handle11179743

    Article  CAS  PubMed  Google Scholar 

  20. R Liu et al. (2000) ArticleTitleRibozyme ablation demonstrates that the cardiac subtype of the voltage-sensitive calcium channel is the molecular transducer of 1,25-dihydroxyvitamin D3-, stimulated calcium influx in osteoblastic cells. J Biol Chem 275 IssueID12 8711–8718 Occurrence Handle10.1074/jbc.275.12.8711 Occurrence Handle1:CAS:528:DC%2BD3cXit1ems7s%3D Occurrence Handle10722713

    Article  CAS  PubMed  Google Scholar 

  21. JG Meszaros et al. (1996) ArticleTitleDown-regulation of L-type Ca2+ channel transcript levels by 1,25-dihyroxyvitamin D3. Osteoblastic cells express L-type α1C Ca2+ channel isoforms. J Biol Chem 271 IssueID51 32981–32985 Occurrence Handle10.1074/jbc.271.51.32981 Occurrence Handle1:CAS:528:DyaK2sXnsFSm Occurrence Handle8955142

    Article  CAS  PubMed  Google Scholar 

  22. AJ Chien et al. (1996) ArticleTitleIdentification of palmitoylation sites within the L-type calcium channel β2a subunit and effects on channel function. J Biol Chem 271 IssueID43 26465–26468 Occurrence Handle10.1074/jbc.271.43.26465 Occurrence Handle1:CAS:528:DyaK28XmsV2rsrc%3D Occurrence Handle8900112

    Article  CAS  PubMed  Google Scholar 

  23. H Haase et al. (1996) ArticleTitle In-vivo phosphorylation of the cardiac L-type calcium channel beta-subunit in response to catecholamines. Mol Cell Biochem 163–164 99–106

    Google Scholar 

  24. MW McEnery TD Copeland CL Vance (1998) ArticleTitleAltered expression and assembly of N-type calcium channel alpha1B and β subunits in epileptic lethargic (lh/lh) mouse. J Biol Chem 273 IssueID34 21435–21438 Occurrence Handle10.1074/jbc.273.34.21435 Occurrence Handle1:CAS:528:DyaK1cXlsFOrtbs%3D Occurrence Handle9705268

    Article  CAS  PubMed  Google Scholar 

  25. T Gao AJ Chien MM Hosey (1999) ArticleTitleComplexes of theα1C and β subunits generate the necessary signal for membrane targeting of class C L-type calcium channels. J Biol Chem 274 IssueID4 2137–2144 Occurrence Handle10.1074/jbc.274.4.2137 Occurrence Handle1:CAS:528:DyaK1MXovVGmsg%3D%3D Occurrence Handle9890976

    Article  CAS  PubMed  Google Scholar 

  26. AC Dolphin et al. (1999) ArticleTitleThe effect of α2-δ and other accessory subunits on expression and properties of the calcium channel α1G. J Physiol 519 35–45 Occurrence Handle1:CAS:528:DyaK1MXmtVWisLk%3D Occurrence Handle10432337

    CAS  PubMed  Google Scholar 

  27. R Felix et al. (1997) ArticleTitleDissection of functional domains of the voltage-dependent Ca2+ channel α2δ subunit. J Neurosci 17 IssueID18 6884–6891 Occurrence Handle1:CAS:528:DyaK2sXmtVKmtLY%3D Occurrence Handle9278523

    CAS  PubMed  Google Scholar 

  28. CA Gurnett M De Waard KP Campbell (1996) ArticleTitleDual function of the voltage-dependent Ca2+ channel α2 δ subunit in current stimulation and subunit interaction. Neuron 16 IssueID2 431–440 Occurrence Handle1:CAS:528:DyaK28XhtlGhsbY%3D Occurrence Handle8789958

    CAS  PubMed  Google Scholar 

  29. SD Jay et al. (1991) ArticleTitleStructural characterization of the dihydropyridine-sensitive calcium channel α 2-subunit and the associated δ peptides. J Biol Chem 266 IssueID5 3287–3293 Occurrence Handle1:CAS:528:DyaK3MXhtlygs78%3D Occurrence Handle1847144

    CAS  PubMed  Google Scholar 

  30. R Eberst et al. (1997) ArticleTitleIdentification and functional characterization of a calcium channel γ subunit. Pflugers Arch 433 IssueID5 633–637 Occurrence Handle10.1007/s004240050324 Occurrence Handle1:CAS:528:DyaK2sXhslClur0%3D Occurrence Handle9049149

    Article  CAS  PubMed  Google Scholar 

  31. XY Wei et al. (1991) ArticleTitleHeterologous regulation of the cardiac Ca2+ channel α 1 subunit by skeletal muscle beta and gamma subunits. Implications for the structure of cardiac L-type Ca2+ channels. J Biol Chem 266 IssueID32 21943–21947 Occurrence Handle1:CAS:528:DyaK3MXmtVWgs78%3D Occurrence Handle1718988

    CAS  PubMed  Google Scholar 

  32. EL Barry et al. (1998) ArticleTitleDistinct calcium channel isoforms mediate parathyroid hormone and chlorothiazide-stimulated calcium entry in transporting epithelial cells. J Membr Biol 161 IssueID1 55–64 Occurrence Handle10.1007/s002329900314 Occurrence Handle1:CAS:528:DyaK1cXltFClsA%3D%3D Occurrence Handle9430621

    Article  CAS  PubMed  Google Scholar 

  33. RT Franceschi BS Iyer Y Cui (1994) ArticleTitleEffects of ascorbic acid on collagen matrix formation and osteoblast differentiation in murine MC3T3-E1 cells. J Bone Miner Res 9 IssueID6 843–854 Occurrence Handle1:CAS:528:DyaK2cXmtVWlt7g%3D Occurrence Handle8079660

    CAS  PubMed  Google Scholar 

  34. Physician’s Desk Reference (2003) Procardia

  35. D Singer et al. (1991) ArticleTitleThe roles of the subunits in the function of the calcium channel. Science 253 IssueID5027 1553–1557 Occurrence Handle1:CAS:528:DyaK3MXmslels7o%3D Occurrence Handle1716787

    CAS  PubMed  Google Scholar 

  36. AL Cahill JH Hurley AP Fox (2000) ArticleTitleCoexpression of cloned α1B, β2a, and α2δ subunits produces non-inactivating calcium currents similar to those found in bovine chromaffin cells. J Neurosci 20 IssueID5 1685–1693 Occurrence Handle1:CAS:528:DC%2BD3cXhsVGmtr0%3D Occurrence Handle10684870

    CAS  PubMed  Google Scholar 

  37. AJ Chien et al. (1995) ArticleTitleRoles of a membrane-localized β subunit in the formation and targeting of functional L-type Ca2+ channels. J Biol Chem 270 IssueID50 30036–30044 Occurrence Handle1:CAS:528:DyaK2MXhtVSitbnE Occurrence Handle8530407

    CAS  PubMed  Google Scholar 

  38. A Hohaus et al. (2002) ArticleTitleThe carboxyl-terminal region of ahnak provides a link between cardiac L-type Ca2+ channels and the actin-based cytoskeleton. Faseb J 16 IssueID10 1205–1216 Occurrence Handle10.1096/fj.01-0855com Occurrence Handle1:CAS:528:DC%2BD38XlslWrtL0%3D Occurrence Handle12153988

    Article  CAS  PubMed  Google Scholar 

  39. PJ Green et al. (2001) ArticleTitleKinetic modification of the alpha1I subunit-mediated T-type Ca2+ channel by a human neuronal Ca2+ channel δ subunit. J Physiol 533 IssueIDPt 2 467–478 Occurrence Handle1:CAS:528:DC%2BD3MXltVSktbs%3D Occurrence Handle11389205

    CAS  PubMed  Google Scholar 

  40. VA Letts et al. (1998) ArticleTitleThe mouse stargazer gene encodes a neuronal Ca2+-channel gamma subunit. Nat Genet 19 IssueID4 340–347 Occurrence Handle1:CAS:528:DyaK1cXlt1Cju7c%3D Occurrence Handle9697694

    CAS  PubMed  Google Scholar 

  41. JL Noebels et al. (1990) ArticleTitleStargazer: a new neurological mutant on chromosome 15 in the mouse with prolonged cortical seizures. Epilepsy Res 7 IssueID2 129–135 Occurrence Handle10.1016/0920-1211(90)90098-G Occurrence Handle1:STN:280:By6C2cnlt1Q%3D Occurrence Handle2289471

    Article  CAS  PubMed  Google Scholar 

  42. D Freise et al. (2000) ArticleTitleAbsence of the δ subunit of the skeletal muscle dihydropyridine receptor increases L-type Ca2+ currents and alters channel inactivation properties. J Biol Chem 275 IssueID19 14476–14481 Occurrence Handle10.1074/jbc.275.19.14476 Occurrence Handle1:CAS:528:DC%2BD3cXjt1Cnsbo%3D Occurrence Handle10799530

    Article  CAS  PubMed  Google Scholar 

  43. AH Sharp et al. (2001) ArticleTitleBiochemical and anatomical evidence for specialized voltage-dependent calcium channel δ isoform expression in the epileptic and ataxic mouse, stargazer. Neuroscience 105 IssueID3 599–617 Occurrence Handle10.1016/S0306-4522(01)00220-2 Occurrence Handle1:CAS:528:DC%2BD3MXmtV2hs7o%3D Occurrence Handle11516827

    Article  CAS  PubMed  Google Scholar 

  44. JG Meszaros NJ Karin MC Farach-Carson (1996) ArticleTitleVoltage-sensitive calcium channels in osteoblasts. mediators of plasma membrane signalling events. Connect Tissue Res 35 IssueID1–4 107–111 Occurrence Handle1:CAS:528:DyaK2sXhvFaht7g%3D Occurrence Handle9084649

    CAS  PubMed  Google Scholar 

  45. LG Raisz (1999) ArticleTitlePhysiology and pathophysiology of bone remodeling. Clin Chem 45 IssueID8 Pt 2 1353–1358 Occurrence Handle1:CAS:528:DyaK1MXltFGnurc%3D Occurrence Handle10430818

    CAS  PubMed  Google Scholar 

  46. GA Rodan et al. (1988) ArticleTitleDiversity of the osteoblastic phenotype. Ciba Found Symp 136 78–91 Occurrence Handle1:STN:280:BiaC2M3lsFc%3D Occurrence Handle3068018

    CAS  PubMed  Google Scholar 

  47. LD Quarles et al. (1992) ArticleTitleDistinct proliferate and differentiated stages of murine MC3T3-E1 cells in culture: an in vitro model osteoblast development. J Bone Miner Res 7 IssueID6 683–692 Occurrence Handle1:STN:280:ByyD3svktlU%3D Occurrence Handle1414487

    CAS  PubMed  Google Scholar 

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Acknowledgements

This work was supported by a grant from the National Institute of Dental and Craniofacial Research (DE 12641) to M.C.F.-C. and minority supplement (DE 12641-S1) to K.A. The authors to thank Mary M. DeSouza for the isolation of mouse skeletal muscle RNA, Erwin Puente for assistance with RT-PCR, and Brian Jensen, Jeffrey A. Kiefer, and Errin L. Lagow for scientific advice.

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Correspondence to M. C. Farach-Carson.

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Bergh, J., Shao, Y., Akanbi, K. et al. Rodent Osteoblastic Cells Express Voltage-Sensitive Calcium Channels Lacking a γ Subunit . Calcif Tissue Int 73, 502–510 (2003). https://doi.org/10.1007/s00223-002-0016-y

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