cDNA cloning of an alternatively spliced isoform of the regulatory subunit of Ca2+/calmodulin-dependent protein phosphatase (calcineurin B alpha 2)

Biochim Biophys Acta. 1994 Mar 1;1217(2):174-80. doi: 10.1016/0167-4781(94)90031-0.


A cDNA encoding the regulatory subunit of Ca2+/calmodulin-dependent protein phosphatase, calcineurin B (CNB), was isolated from a rat testis cDNA library. It differs from the cDNA obtained from a rat brain cDNA library by an addition of 138 base pairs in the coding region. The codon of the clone from a testis library corresponding to the initiation codon of the clone from a brain library is not ATG but AAG, 5'-noncoding regions of these cDNAs are also different. The addition in the coding region results in the gain of 46 amino acids at the N-terminus. These findings suggest that two distinct isoforms of CNB alpha are derived from the same gene through a process involving alternative utilization of two promoters. We designate the brain type isoform as CNB alpha 1 and the longer isoform as CNB alpha 2. Northern blot analysis and reverse transcriptase-polymerase chain reaction (RT-PCR) followed by Southern blot analysis suggest that CNB alpha 2 is specifically expressed in the testis, and its expression is developmentally regulated.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Brain / metabolism
  • Calcineurin
  • Calmodulin-Binding Proteins / genetics*
  • Cloning, Molecular
  • DNA, Complementary / chemistry
  • DNA, Complementary / genetics*
  • DNA, Complementary / isolation & purification
  • Male
  • Molecular Sequence Data
  • Phosphoprotein Phosphatases / genetics*
  • Polymerase Chain Reaction
  • Rats
  • Testis / metabolism


  • Calmodulin-Binding Proteins
  • DNA, Complementary
  • calcineurin Balpha2
  • Calcineurin
  • Phosphoprotein Phosphatases

Associated data

  • GENBANK/D14425
  • GENBANK/D14568