PRRX1

Paired related homeobox 1 is a is_associated_with::protein that in humans is encoded by the PRRX1 is_associated_with::gene.

Function
The DNA-associated protein encoded by this gene is a member of the paired family of is_associated_with::homeobox proteins localized to the nucleus. The protein functions as a is_associated_with::transcription coactivator, enhancing the DNA-binding activity of is_associated_with::serum response factor, a protein required for the induction of genes by growth and differentiation factors. The protein regulates muscle is_associated_with::creatine kinase, indicating a role in the establishment of diverse is_associated_with::mesodermal muscle types. Alternative splicing yields two isoforms that differ in abundance and expression patterns.

Role in mesenchymal stem cell differentiation
Prrx1 expression is restricted to the is_associated_with::mesoderm during is_associated_with::embryonic development, and both Prrx1 and Prrx2 are expressed in is_associated_with::mesenchymal tissues in adult mice. Mice that lack both Prrx1 and Prrx2 have profound defects in mesenchymal cell differentiation in the is_associated_with::craniofacial region. Several recent studies demonstrate that PRRX1 can regulate differentiation of mesenchymal precursors. For example, PRRX1 inhibits adipogenesis by activating is_associated_with::transforming growth factor-beta (TGF-beta) signaling, and also acts downstream of is_associated_with::tumor necrosis factor-alpha to inhibit is_associated_with::osteoblast differentiation.