Serine/Threonine Kinase 16 (STK16)

The STK16 gene encodes a 310-amino acid protein that shares 94% identity with the mouse homolog. Because its size is very close to the minimal size for a core catalytic domain, the authors suggested that STK16 may constitute the catalytic subunit of a multisubunit kinase.

Gel shift analysis indicated that Tsf1 is a sequence-specific DNA-binding factor that binds to GC-rich elements in vascular endothelial growth factor (VEGF) and type C natriuretic peptide (NPPC) promoters, independent of its kinase activity and Smad3 or Smad4. Tsf1 could not directly activate the Smad-dependent promoter of plasminogen activator inhibitor-1 (PAI1) but could enhance the transactivation function of Smad3 and Smad4.