Molecular Neurobiology

, 37:164 | Cite as

Acetylcholine Receptor γ-Subunits mRNA Isoforms expressed in Denervated Rat Muscle

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Abstract

The fetal acetylcholine (ACh) receptor, composed of the αβγδ subunits, is expressed in fetal, neonatal, and denervated muscle. Single-channel recording has revealed three kinetically distinct classes in neonatal and denervated muscle, suggesting that at least three forms of the γ-subunit are required. To account for the kinetic classes observed, we compared the messenger ribonucleic acid (mRNA) forms expressed in neonatal and denervated muscle using reverse transcriptase polymerase chain reaction, cloning, and RNAse protection assays. We found five novel forms arising from alternative splicing, which we named γ5–γ9. The forms γ5, γ6, and γ7 lack exon 4 and 63-, 89-, and 136 bp of exon 5, respectively. A γ8 form lacks exons 3 and 4 and 19 bp of exon 5. The last, γ9, lacks exons 3, 4, and 5. Results indicate that γ4 predominates in fetal muscle and γ7 in denervated adult muscle. Some of the γ-subunit mRNAs found may generate the receptors observed in muscle.

Keywords

γ-Subunits mRNA isoform Acetylcholine receptor AChR Endplate channel Splice variant 
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Notes

Acknowledgments

This work was partially supported by NSERC Canada (Grant 227298-02 to AV). We are grateful to Dr. P. Murphy for discussions and critical reading of the manuscript and to Ms J. Froom for expert technical assistance.

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Copyright information

© Humana Press Inc. 2008

Authors and Affiliations

  • Amanda M. Li
    • 1
  • Hualong Ma
    • 1
  • Alfredo Villarroel
    • 1
    • 2
  1. 1.Department of Physiology and BiophysicsDalhousie University School of MedicineHalifaxCanada
  2. 2.Department of Physiology, Faculty of ScienceMahidol UniversityBangkokThailand

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