A protein called Nix is vital in the maturation process of red blood cells, American scientists have found.
Dr. Jin Wang, an assistant professor of Immunology at Baylor College of Medicine in Houston, says that Nix gives necessary instructions to the cells regarding a process of self-digestion called autophagy, which prompts their maturation.
The researcher says that without the protein, the cells would not effectively rid themselves of organelles called mitochondria, and consequently become short-lived, leading to anaemia.
"It's changed our thinking on autophagy," Nature magazine quoted Dr. Wang, senior author on the study, as saying.
During autophagy, the cell forms an envelope or vesicle around components of the cell that need to be degraded and removed. Thereafter, the vesicle fuses with a cellular component called a lysosome that degrades its contents.
"This is not a random process. Nix is instructing the cell to get rid of these mitochondria," said Dr. Wang.
"We think the finding is not limited to the clearance of mitochondria in red blood cells. When other cells get old or stressed, their organelles may become damaged and need to be cleared by autophagy for quality control. If the cells lack such quality controls, they might have problems that result in aging, cancer and neurodegenerative diseases.
"It helps get rid of old or damaged mitochondria. It is a way to keep the cell functioning without going through programmed cell death (apoptosis)," he added.
Dr. Min Chen, assistant professor of immunology at BCM and a corresponding author of this work, said: "Such specific regulation of autophagy may also be important for cell types in the muscle, brain and pancreas. The next step is to identify proteins interacting with Nix for mitochondrial quality control by autophagy."
Hector Sandoval, a BCM graduate student who is the first author of the study, believes that besides Nix, other factors may also regulate the process.