Alternative titles; symbols
HGNC Approved Gene Symbol: PTH2
Cytogenetic location: 19q13.33 Genomic coordinates (GRCh38) : 19:49,422,419-49,423,441 (from NCBI)
PTH2, also known as TIP39, is related to parathyroid hormone (PTH; 168450) and PTH-related protein (PTHRP; 168470) and is a ligand for PTH receptor-2 (PTHR2; 601469) (John et al., 2002).
By searching a database for sequences similar to bovine Tip39, followed by 5-prime RACE of a hypothalamus cDNA library, John et al. (2002) cloned TIP39. The deduced 100-amino acid precursor protein contains a signal peptide cleavage site and a dibasic cleavage site for release of a mature secreted 39-amino acid hormone. The secreted peptide shares 100% amino acid identity with bovine Tip39. John et al. (2002) also cloned mouse Tip39 from brain total RNA. The deduced 100-amino acid mouse precursor protein shares 78% identity with the human precursor, and the secreted peptides share 97% identity. Northern blot analysis of mouse tissues detected a 4.5-kb Tip39 transcript expressed at a high level in testis and at low levels in liver, kidney, and possibly heart. Larger transcripts were also expressed in testis, and shorter transcripts were weakly expressed in liver and whole brain. In situ hybridization detected mouse Tip39 mRNA in epithelium of seminiferous tubules and in several brain regions, including nucleus ruber, nucleus centralis pontis, and nucleus subparafascicularis thalami. Phylogenic analysis suggested that TIP39, PTH, and PTHRP may have evolved from a common ancestor.
John et al. (2002) demonstrated that mouse and human TIP39 activated PTHR2 following transfection in porcine kidney cells. An N-terminally truncated form of TIP39 containing only amino acids 9 to 39 inhibited PTHR2 activation by PTH.
John et al. (2002) determined that the TIP39 gene contains at least 3 exons. Exon 1 is untranslated, and exon 3 encodes the entire secreted peptide.
By genomic sequence analysis, John et al. (2002) mapped the TIP39 gene (PTH2) to chromosome 19q13.33.
John, M. R., Arai, M., Rubin, D. A., Jonsson, K. B., Juppner, H. Identification and characterization of the murine and human gene encoding the tuberoinfundibular peptide of 39 residues. Endocrinology 143: 1047-1057, 2002. [PubMed: 11861531] [Full Text: https://doi.org/10.1210/endo.143.3.8698]