Cloning of a Xenopus laevis muscarinic receptor encoded by an intronless gene

FEBS Lett. 1994 Sep 26;352(2):175-9. doi: 10.1016/0014-5793(94)00957-0.


The Xenopus laevis oocyte has endogenous sites that bind muscarinic agonists, which have been pharmacologically characterized as M3 and/or M1 receptor subtypes. In order to define the molecular identify of the receptor protein we have analyzed a Xenopus oocyte cDNA library and cloned a 2.9 kb cDNA fragment encoding a muscarinic receptor (xMR). The deduced amino acid sequence reveals a protein of 484 residues with an apparent molecular weight of 54,188 Da. Amino acid comparison with previously cloned mammalian muscarinic receptors showed a 78% identity with the human m4 subtype, presenting at the same time clustered differences within the amino-terminal region and third intracellular loop Genomic Southern analysis displayed the presence of one main gene belonging to this subtype, and the PCR analysis revealed an intronless gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular*
  • DNA, Complementary
  • Genes / genetics*
  • Humans
  • Introns
  • Molecular Sequence Data
  • Molecular Weight
  • Oocytes
  • Open Reading Frames / genetics
  • Receptors, Muscarinic / chemistry
  • Receptors, Muscarinic / genetics*
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Xenopus laevis / genetics


  • DNA, Complementary
  • Receptors, Muscarinic

Associated data

  • GENBANK/X65865