Transmembrane Protein 121 (TMEM121)

Hole is a novel gene product isolated from a chick heart subtractive hybridization. Hole is a six-transmembrane protein (predicted size 311 and 317 amino acids in chick and mouse) expressed in the cardiac crescent and later in the myocardium of the developing chick heart, as well as in the fusing neural tube and ganglia. Mouse hole is not expressed in the developing heart, although it does share neural expression seen in the chick.The human hole gene, hhole, is a 319-amino acid six-transmembrane protein with proline-rich C-terminal motifs and N-terminal ERK binding domains (D-domains). The hhole protein is highly conserved in evolution across different species from elegent, mouse to human. hole is expressed in heart, liver, skeletal muscle, and pancreas at adult stages and in most of the examined embryonic tissues, especially at a higher level in heart.