This domain family is found in eukaryotes, and is approximately 50 amino acids in length. The family is found in association with Pfam:PF00307. Smoothelin is a cytoskeletal protein specifically expressed in differentiated smooth muscle cells and has been shown to co-localize with smooth muscle alpha actin.

1: Identification and characterization of novel smoothelin isoforms in vascular smooth muscle. Kramer J, Quensel C, Meding J, Cardoso MC, Leonhardt H; J Vasc Res. 2001;38:120-132. PMID:11316948