Transcriptional analysis of the PTEN/MMAC1 pseudogene, psiPTEN.
PTEN/MMAC1 is a recently characterized tumor suppressor. A pseudogene derived from the human PTEN/MMAC1 phosphatase, psiPTEN, has been reported. Recent analysis of the pseudogene revealed conflicting results about the expression of psiPTEN. In this study, we show that the PTEN/MMAC1 pseudogene is actively transcribed in all cells and tissues examined. In some cases, pseudogene transcripts were found to represent as much as 70% of the total PTEN/MMAC1 RNA. As psiPTEN is transcribed, there is a potential for misinterpretation of PTEN/MMAC1 mutations when RT-PCR techniques are used, as well as potential for a psiPTEN-encoded translation product. Although we were unable to detect a pseudogene protein product in the cell lines examined, a baculovirus produced GST pseudogene fusion protein exhibited phosphatase activity comparable to wild type. The results of this study, taken together, indicate the potential complication of PTEN/MMAC1 molecular analysis caused by the expression of psiPTEN.
Fujii
G H
GH
Department of Cellular Signaling, DNAX Research Institute, Palo Alto, California 94304, USA.
Morimoto
A M
AM
Berson
A E
AE
Bolen
J B
JB
D000595:Amino Acid Sequence; D001483:Base Sequence; D018076:DNA, Complementary; D015870:Gene Expression; D016147:Genes, Tumor Suppressor; D006801:Humans; D008969:Molecular Sequence Data; D051059:PTEN Phosphohydrolase; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics* / Q000378:metabolism; D011544:Pseudogenes; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
D018076:DNA, Complementary; D025521:Tumor Suppressor Proteins; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human