Smoothelin-like protein 1 (SMTNL1)

Smoothelin-like protein 1 (SMTNL1) is an actin-binding protein primarily expressed in smooth muscle, skeletal muscle, and steroid hormone-responsive tissues. It serves as both a regulator of muscle contractility—acting through modulation of myosin phosphatase (MP) and its regulatory subunit MYPT1—and a nuclear transcriptional co-regulator, especially influencing progesterone receptor-B signaling. SMTNL1 is implicated in the regulation of insulin sensitivity by enhancing the expression of genes such as GLUT4 and IRS1, and attenuating insulin resistance by inhibiting JNK activity and modulating ERK1/2 signaling. SMTNL1 is phosphorylated at Ser301 (by protein kinase A/protein kinase G), enabling its translocation to the nucleus to modulate gene expression, affecting processes including glucose metabolism, muscle adaptation to physiological stress (such as pregnancy and exercise), and possibly reproductive fitness. While it is not a typical therapeutic target (e.g., receptor, enzyme, channel), its pivotal roles in metabolism and hormone signaling make it of emerging biological and potential therapeutic interest[1][2][3].

Other names

Calponin homology-associated smooth muscle proteinCHASMsmoothelin like 1SMTNL1smoothelin-like protein 1calponin homology-associated smooth muscle protein