Expression of the gene and processed pseudogenes encoding the human and rabbit translationally controlled tumour protein (TCTP)

In humans and rabbits, the TPT1 gene encoding the translationally controlle d tumour protein TCTP generates two mRNAs (TCTP mRNA1 and TCTP mRNA2) which differ in the length of their 3' untranslated regions. The distribution of these mRNAs was investigated in 10 rabbit and 50 human tissues. They were transcribed in all tissues investigated, but differed considerably in their quantity and ratio of expression. This indicates an extensive transcriptio nal control and involvement of tissue-specific factors. In the rabbit genom e numerous processed, intronless pseudogenes were detected. Four, correspon ding to both types of mRNAs, were sequenced and analysed in detail; all dis played only few mutations and were either preserved completely in the origi nal amino acid sequence of the intron containing gene, or contained only mi nor mutations in the coding region which did not interrupt the open reading frame. In the mRNA population of rabbit reticulocytes two additional TCTP RNAs of the TCTP mRNA2 type were detected, which have the characteristics o f pseudogene transcripts. Pseudogene transcription was supported further by CAT reporter gene assays showing substantial promoter activity of 5'-flank ing regions of two TPT1 pseudogenes.