The Sec61 complex is a critical protein-conducting channel in the endoplasmic reticulum (ER) membrane that facilitates the translocation and integration of nascent polypeptides. It plays a central role in the secretory pathway, ensuring proteins reach their correct cellular destinations and assists in maintaining cellular homeostasis by handling misfolded proteins through ER-associated degradation.

Sec61 Complex

Sec61 complex

protein-conducting channel

The endoplasmic reticulum (ER) is a vital cellular organelle responsible for the synthesis, folding, modification, and transport of proteins and lipids. It exists in two forms: rough ER, studded with ribosomes for protein synthesis, and smooth ER, which is involved in lipid synthesis and detoxification processes.

endoplasmic reticulum

Translocation of nascent polypeptides

integration of nascent polypeptides

The secretory pathway is a cellular process that involves the synthesis, folding, modification, and transport of proteins from the endoplasmic reticulum to their final destinations, such as the cell surface or extracellular space. This pathway is crucial for maintaining cellular homeostasis and facilitating communication between cells through the secretion of hormones, enzymes, and other proteins.

secretory pathway

cellular destinations

Cellular homeostasis refers to the processes by which cells maintain a stable internal environment, crucial for optimal function and survival. It involves a dynamic balance of inputs and outputs, regulating factors such as pH, ion concentration, and nutrient levels to adapt to changes both inside and outside the cell.

cellular homeostasis

Misfolded proteins are proteins that fail to achieve their biologically functional three-dimensional structure, often leading to cellular dysfunction and disease. These aberrant proteins can aggregate, disrupting normal cellular processes and are implicated in various neurodegenerative disorders like Alzheimer's and Parkinson's disease.

misfolded proteins

ER-associated degradation (ERAD) is a cellular quality control mechanism that identifies and retrotranslocates misfolded or surplus proteins from the endoplasmic reticulum (ER) to the cytosol for ubiquitination and subsequent proteasomal degradation. This process maintains protein homeostasis and prevents the accumulation of toxic protein aggregates in the ER, which is crucial for proper cellular function.

CUSTOMIZE YOUR LEARNING

CUSTOMIZE YOUR LEARNING