What types of secretion are controlled by the Golgi complex?
The Golgi complex controls trafficking of different types of proteins. Some are destined for secretion. Others are destined for the extracellular matrix. Finally, other proteins, such as lysosomal enzymes, may need to be sorted and sequestered from the remaining constituents because of their potential destructive effects. This figure shows the two types of secretory pathways. The regulated secretory pathway, as its name implies, is a pathway for proteins that requires a stimulus or trigger to elicit secretion. Some stimuli regulate synthesis of the protein as well as its release. The constitutive pathway allows for secretion of proteins that are needed outside the cell, like in the extracellular matrix. It does not require stimuli, although growth factors may enhance the process.
Finally, this cartoon also shows the packaging of lysosomes which will be discussed in more detail in a later section. For more information go to the lysosome web page.