Sec61p

Sec61p is a conserved protein complex found in the endoplasmic reticulum of eukaryotic cells. It forms the translocation channel that facilitates the passage of proteins across the ER membrane. The complex is composed of three subunits: Sec61α, Sec61β, and Sec61γ. Sec61p plays a critical role in protein biogenesis, enabling newly synthesized polypeptides to enter the ER lumen or integrate into the ER membrane. This process is essential for the proper folding, modification, and trafficking of many proteins, including secreted proteins, membrane proteins, and lysosomal proteins. The Sec61p channel is dynamic and can exist in different conformations, allowing for the translocation of various types of polypeptide chains. It is also involved in signal peptide recognition and cleavage. Beyond its canonical role in protein translocation, Sec61p has been implicated in other cellular processes, such as calcium homeostasis and ER stress response, highlighting its multifaceted functions within the cell. The precise mechanisms governing Sec61p function and its regulation are areas of ongoing research.