Structure of the promoter and complete sequence of the gene coding for the rabbit translationally controlled tumor protein (TCTP) P23

Abstract

We have isolated genomic recombinants containing the complete gene coding for the rabbit translationally controlled tumor protein (TCTP), also known as histamine-releasing factor (HRF) P23. The gene is organized into five introns and six exons and its total length amounts to 3819 nucleotides. All intron/ exon boundaries are in accordance with the GT/AG rule. Transcription of the gene generates two mRNAs of 843 and 1163 nucleotides differing in the length of their 3′-untranslated regions. They are formed by alternative polyadenylation. The transcription initiation site has been determined by comparison of sequences of the gene and several processed TCTP pseudogenes. The full-length 5′-untranslated region comprises 116 nucleotides and starts with an oligopyrimidine tract important for translational regulation. Additionally 1.2 kb of the 5′-flanking promoter region has been sequenced. The promoter contains a TATA box at Ϫ30 and potential binding sites for transcription factors such as stimulating protein 1 (Sp1), nuclear factor 1 (NF1), activator protein 1 (AP1), c-Ets1, cAMP-response element (CP2), myeloid-specific zinc finger protein 1 (MZF1) and others. For functional analysis 5′-flanking sequences up to Ϫ918 were fused to the chloramphenicol acetyltransferase (CAT) gene and tested using a rabbit aortic smoothmuscle cell line by cell transfection and CAT assays. The results confirm that the analyzed gene is the actively transcribed TCTP gene.Keywords : translationally controlled tumor protein; histamine-releasing factor; gene organization ; promoter; pseudogenes.The translationally controlled tumor protein (TCTP) was described initially by Brawerman's group [1] as a growth-related protein in mouse ascites and erythroleukemic cells whose mRNA is stored as translationally inactive mRNP complexes. The mouse protein was also designated as p21 [2] and the human homologue as p23 [3]. TCTP is a highly conserved fairly abundant protein which is found not only in mammals but also in many other species, including nematodes [4], trypanosomes [5], and plants [6]. Recent studies have shown that the term 'TCTP' is somewhat misleading because it is definitely not a protein restricted to tumor cells [7]. This situation is further complicated by experiments showing that TCTP can act on basophils of atopic patients in an IgE-dependent way as a histamine releasing factor [8]. Furthermore TCTP has been described as a protein which binds calcium with high affinity, but does not belong to any known family of calcium-binding proteins [5,9].Despite the fact that its physiological role is currently not clearly defined, the regulation of expression of TCTP demands Correspondence to B.-J. Thiele,

The Translational Controlled Tumour Protein TCTP: Biological Functions and Regulation

“…The first structure of a TPT1 gene (for rabbit) was characterised in Bernd Thiele's group in Berlin; the gene was found to comprise about 4000 nucleotides, beginning at the transcription start site, and to consist of 6 exons and 5 introns, where the last exon comprises the entire 3 0 -UTR of the mRNA (Thiele et al 1998). A very similar structure was also reported for the mouse (Fiucci et al 2003) and the human (Andree et al 2006) TPT1 gene.…”

“…The promoter regions of the active TPT1 gene were further investigated for the rabbit (Thiele et al 1998), mouse (Fiucci et al 2003) and human (Andree et al 2006) genes. They displayed a large number of transcription factor-binding motifs, i.e.…”

“…. for the human, mouse and rabbit mRNAs (Thiele et al 1998(Thiele et al , 2000Fiucci et al 2003). The 5 0 -TOP motif is a hallmark for a specific group of mRNAs that are under translational control through the mTOR complex 1 (mTORC1) signalling pathway (Meyuhas and Kahan 2015;Yamashita et al 2008).…”

Antiapoptotic Protein Partners Fortilin and MCL1 Independently Protect Cells from 5-Fluorouracil-induced Cytotoxicity

“…It is possible that fortilin expression was up-regulated by unknown transcriptional factors, thus masking the destabilization of fortilin attributable to the lack of MCL1. The transcriptional regulation of fortilin appears to be very complex (27), and further investigation is needed to evaluate the role of various pathways in it.…”

Cellular Function and Regulation of the Translationally Controlled Tumour Protein TCTP

“…Initially, they described the gene structure and upstream promoter sequences of the TCTP gene from rabbit and humans and established that these regions contain several promoter elements that are wellconserved in mammals. They also showed that, as a whole, this upstream region exhibits a strong promoter activity [100]. In a second report, the group characterised various features of TCTP mRNAs.…”