TPT1 Human

Tumor Protein Translationally-Controlled 1 (TPT1), also known as Translationally Controlled Tumor Protein (TCTP), is a highly conserved protein found in various eukaryotic species. It is encoded by the TPT1 gene in humans, which is located on chromosome 13 (13q12-q14) and contains five introns and six exons . TPT1 is known by several aliases, including p23, Fortilin, and Histamine-Releasing Factor (HRF) .

TPT1 was first discovered in 1989 as a cDNA sequence obtained from a human mammary carcinoma cDNA library . Initially described as a growth-related protein of tumor cells, TPT1 mRNA accumulates in translationally repressed postpolysomal mRNP-complexes . Over time, research revealed that TPT1 is not tumor- or tissue-specific but is ubiquitously expressed across various tissues and cell types .

TPT1 is a 20-25 kDa protein that is abundantly and ubiquitously expressed in cells . The protein contains a promoter with a canonical TATA-box and several promoter elements that are well-conserved in mammals . TPT1 mRNA is highly structured and contains an oligopyrimidine tract (5’-TOP) in its 5’ untranslated region, which functions to repress its translation under quiescent conditions .

TPT1 is involved in a variety of cellular pathways, including apoptosis, protein synthesis, and cell division . It binds to and stabilizes microtubules, and its removal through phosphorylation is required for progression through mitotic and meiotic cell divisions . TPT1 also plays a role in calcium binding and microtubule stabilization . Additionally, it acts as a negative regulator of TSC22D1-mediated apoptosis by interacting with and destabilizing the TSC22D1 protein .

TPT1 is frequently overexpressed in cancers, where high levels are often associated with poor patient outcomes . It is involved in protecting cancer cells against the cytotoxic action of anti-cancer drugs . TPT1’s role in carcinogenesis is further supported by its upregulation in some cancer cells .