Receptor-evoked Cl- current in Xenopus oocytes is mediated through a beta-type phospholipase C. Cloning of a new form of the enzyme

J Biol Chem. 1993 Sep 25;268(27):19915-8.

Abstract

Xenopus oocytes exhibit a receptor-evoked Cl- current that is mediated through the activation of phospholipase C (PLC) and release of intracellular Ca2+. The identity of PLC(s) mediating this effect is unknown. We have cloned cDNAs encoding a new form of PLC-beta from a Xenopus oocyte cDNA library. The Xenopus PLC-beta has substantial (33-64%) homology with mammalian beta 1, beta 2, beta 3, and beta 4 phospholipase C and is closest to PLC-beta 3, with 64% identity and 80% similarity. Injection of antisense oligonucleotides to a specific region of Xenopus PLC-beta results in degradation of its mRNA and significantly reduces Cl- currents evoked by both endogenous angiotensin receptors and expressed mammalian alpha 1b-adrenergic receptors and M1-muscarinic receptors as compared to responses in sense oligonucleotide-injected oocytes. Inhibition of the M1-muscarinic response by antisense oligonucleotides was nonadditive with pertussis toxin inhibition. PLC antisense oligonucleotide-injected oocytes show Cl- current responses to IP3 that are indistinguishable from sense oligonucleotide-injected oocytes. Since the receptor responses are pertussis toxin-sensitive, we conclude that we have isolated a new form of PLC-beta involved in the pertussis toxin-sensitive receptor stimulation of the Ca2+ activated Cl- current in Xenopus oocytes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Chloride Channels
  • Chlorides / metabolism*
  • Cloning, Molecular
  • Drosophila / enzymology
  • Drosophila / genetics
  • Female
  • Gene Library
  • Isoenzymes / biosynthesis
  • Isoenzymes / genetics
  • Isoenzymes / metabolism*
  • Mammals
  • Membrane Proteins / drug effects
  • Membrane Proteins / physiology*
  • Molecular Sequence Data
  • Oligodeoxyribonucleotides
  • Oligonucleotides, Antisense / pharmacology
  • Oocytes / drug effects
  • Oocytes / enzymology*
  • Oocytes / physiology
  • Pertussis Toxin
  • RNA, Messenger / metabolism
  • Receptors, Adrenergic, alpha / biosynthesis
  • Receptors, Adrenergic, alpha / physiology*
  • Receptors, Angiotensin / physiology*
  • Receptors, Muscarinic / biosynthesis
  • Receptors, Muscarinic / physiology*
  • Type C Phospholipases / biosynthesis
  • Type C Phospholipases / genetics
  • Type C Phospholipases / metabolism*
  • Virulence Factors, Bordetella / pharmacology
  • Xenopus

Substances

  • Chloride Channels
  • Chlorides
  • Isoenzymes
  • Membrane Proteins
  • Oligodeoxyribonucleotides
  • Oligonucleotides, Antisense
  • RNA, Messenger
  • Receptors, Adrenergic, alpha
  • Receptors, Angiotensin
  • Receptors, Muscarinic
  • Virulence Factors, Bordetella
  • Pertussis Toxin
  • Type C Phospholipases

Associated data

  • GENBANK/L20816