Structure of the mouse gene encoding parathyroid hormone-related peptide.

The parathyroid hormone-related peptide (PTHRP) was initially isolated from tumors associated with the syndrome of humoral hypercalcemia of malignancy. The human PTHRP gene is a complex transcriptional unit which uses multiple promoters and contains alternatively spliced 3' exons that result in mRNAs encoding three different deduced products. We report here the structure of the mouse PTHRP gene. The mouse gene has a considerably simpler organization than its human counterpart. This organization includes a single 3' exon and an apparent single 3' splicing pathway, leading to an mRNA encoding a 139-amino acid mature PTHRP. In addition, the mouse gene appears to be predominantly under the control of a short proximal promoter element. By RNase protection analysis, we identified PTHRP mRNA in specimens prepared from a variety of normal rodent tissues, including a number of tissues not previously recognized as sites of PTHRP gene expression.