RT-PCR cloning of Rab3 isoforms expressed in peritoneal mast cells

Andreas F. Oberhauser, Vijayan Balan, Carmen L. Fernandez-Badilla, Julio M. Fernandez

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


Rab proteins are ras-like low molecular mass GTP-binding proteins, which are postulated to act as specific regulators of membrane trafficking in exocytosis and endocytosis. We have previously shown that synthetic peptides, corresponding to the effector domain of Rab3 proteins, stimulate a complete exocytotic response in mast cells. We have used a PCR-eloning strategy to investigate the presence of mRNA encoding Rab3 in mast cells. RNA based PCR was then performed on mast cell RNA using degenerate oligonucleotide primers based on two conserved sequences among Rab3 proteins. However, no PCR products were obtained, even for proteins known to be expressed in high copy numbers in mast cells (β-actin and Fc receptor). We have found that the problem resides in the presence of mast cell secretory granule derived heparin, that copurifies with the RNA; heparin has been shown to inhibit the activity of reverse transcriptase and Taq polymerase in PCR. After treating the RNA (obtained from about 500 mast cells) with heparinase, several PCR products of varying size were obtained using primers specific for Rab3 proteins. These products were cloned and sequenced. We have found clones containing sequences that had a 100% homology at the deduced amino acid level to a portion of Rab3B and Rab3D (amino acids 16 to 83).

Original languageEnglish (US)
Pages (from-to)171-174
Number of pages4
JournalFEBS Letters
Issue number1-2
StatePublished - Feb 14 1994
Externally publishedYes


  • Heparin inhibition
  • PCR cloning
  • Peritoneal mast cell
  • RT-PCR
  • Rab3 protein

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology


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