Slowing Down To Take It In: Endocytosis During Cellular Aging
Our cells are constantly working to maintain themselves, including a vital process called endocytosis, which is how they take in substances from their external environment. Think of it like the cell’s recycling and intake system, crucial for clearing out damaged components from its surface and bringing in necessary nutrients. New research sheds light on how this essential process changes as cells get older.
Scientists have found that in aging cells, a specific type of intake, known as clathrin-mediated endocytosis, significantly slows down. This particular pathway involves a protein called clathrin that helps form small pockets on the cell’s outer boundary, or plasma membrane, to capture and internalize materials. The slowdown appears to be linked to a change in the internal waste-processing compartments of the cell, called vacuoles. As cells age, the pH inside these vacuoles becomes more alkaline (less acidic). This shift in alkalinity then disrupts a key cellular communication pathway, known as TORC1 signaling, which in turn affects how effectively the cell can load materials into these intake pockets.
The consequence of this reduced cellular “cleanup” is that damaged proteins and other unwanted substances can accumulate on the cell’s surface. This accumulation is not just a minor inconvenience; it has significant implications for overall cellular health and is thought to contribute to various age-related diseases, including neurodegenerative conditions like Alzheimer’s, where the buildup of problematic protein clumps is a hallmark.
Source: link to paper