Sec16p

Sec16p is a protein that plays a crucial role in the endoplasmic reticulum (ER) to Golgi transport pathway. It is a component of the COPII (coat protein complex II) coat, which is responsible for the formation of transport vesicles that bud from the ER and deliver cargo to the Golgi apparatus. Sec16p is a small GTPase that cycles between an active GTP-bound state and an inactive GDP-bound state. In its active form, Sec16p interacts with other COPII components, such as Sec23p and Sec24p, to facilitate the recruitment of cargo proteins and the assembly of the COPII coat around the transport vesicle. Once the vesicle is formed, Sec16p hydrolyzes its bound GTP to GDP, releasing the coat and allowing the vesicle to fuse with the Golgi apparatus. Sec16p is essential for various cellular processes, including protein secretion, protein sorting, and quality control. Mutations in the SEC16 gene, which encodes Sec16p, have been linked to several human diseases, including Charcot-Marie-Tooth disease type 2A (CMT2A) and Alström syndrome.