An Israeli researcher at the Weizmann Institute of Science in Rehovot is studying a part of human biological quality control that she calls “the cell’s shipping and packing department.”
Actually, it’s a structure known as the endoplasmic reticulum (ER) – a specialized compartment in each human cell that controls the quality of every protein that is produced, packages it correctly and sends it on to its proper destination.
Dr. Maya Schuldiner of the Department of Molecular Genetics at the Weizmann Institute of Science told the WeizmannViews that she studies this specialized compartment “because it has such an enormous responsibility.”
On example she uses is a description of the role of the ER in nerve cells.
In order for the brain to process information, nerve cells transmit messages to other nerve cells in the form of electrical signals. But “the only reason those electrical signals can move through your brain is because of proteins on the cell surface that allow them to pass through,” Schuldiner says. “Those proteins are all made in the ER, which has to function non-stop in an optimal manner to produce enough of them.”
Schuldiner uses baker’s yeast (Saccharomyces cerevisiae) for her research, because yeast cells are similar to human cells, but divide much more rapidly. They are also easier to manipulate in the lab.
All human cells need to have a properly functioning ER in order to stay healthy. Conditions such as diabetes, heart disease, immunological and neurological disorders can develop when the ER is not working correctly.
A B cell (a type of white blood cell that helps protect the body from bacterial infections) will double in size when it encounters an antigen (foreign substance, such as a bacteria) in order to house enough ER to manage the number of proteins – antibodies -- required to fight the battle against the disease.
If the ER does not function properly in the B cells, however, one can develop an immune deficiency, because antibodies are not being produced properly. In a diabetic, this means the ER in the pancreatic cells have stopped working – thus no insulin is being produced to process sugar in the body.
“My hope is to understand how the ER – this very basic machinery that is essential for the function of every single cell type in our body – works during the normal life of a cell and during disease,” Schuldiner explains.