Nixing immaturity in red blood cells

May 4, 2008

A process of self-digestion called autophagy prompts the maturation of red blood cells. Without a protein called Nix, the cells would not effectively rid themselves of organelles called mitochondria and consequently become short-lived, leading to anemia, said researchers at Baylor College of Medicine in Houston in a report that appears online today in the journal Nature.

“It’s changed our thinking on autophagy,” said Dr. Jin Wang, assistant professor of immunology at BCM and senior author of the report. During autophagy, the cell forms an envelope or vesicle around components of the cell that need to be degraded and removed. The vesicle then fuses with a cellular component called a lysosome that degrades its contents. The inclusion of components in the cell by autophagy vesicles was generally considered to be nonspecific.

“This is not a random process,” said Wang. “Nix is instructing the cell to get rid of these mitochondria.”

Nix accomplishes this task by disrupting the mitochondrial membrane potential (represented by difference in voltage across the inner membrane of the mitochondria. The interior is negative and the outside positive. The difference generates a force that drives the synthesis of ATP, the cell’s energy molecule).

“We think the finding is not limited to the clearance of mitochondria in red blood cells,” said Wang. “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,” he said. “It is a way to keep the cell functioning without going through programmed cell death (apoptosis).”

“Such specific regulation of autophagy may also be important for cell types in the muscle, brain and pancreas,” said Dr. Min Chen, assistant professor of immunology at BCM and a corresponding author of this work. “The next step is to identify proteins interacting with Nix for mitochondrial quality control by autophagy”. Other factors may also regulate this process in addition to Nix, said Hector Sandoval, a BCM graduate student who is the first author of this paper.

Source: Baylor College of Medicine

Explore further: Specific protein promotes development of pancreatitis and tumours

Related Stories

Specific protein promotes development of pancreatitis and tumours

December 5, 2017
Pancreatic cancer is one of the most aggressive forms of cancer and is currently very difficult to treat. However, the last few years have seen advances in the scientific understanding of how this cancer develops at a molecular ...

Study reveals new mechanisms of cell death in neurodegenerative disorders

November 22, 2017
Researchers at King's College London have discovered new mechanisms of cell death, which may be involved in debilitating neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease.

Antimalarial drugs could support existing cancer treatments in two-pronged attack

November 23, 2017
Antimalarial drugs chloroquine and hydroxychloroquine could find another use as cancer treatments, according to a new clinical study published in ecancermedicalscience.

Bringing natural killer cells to the tumor battlefield

November 8, 2017
Natural Killer (NK) cells, lymphocytes of the innate immune system with strong cytotoxic activity, play a major role in the immune response against tumors. However, tumor cells can circumvent this immune defense by establishing ...

A new compound targets energy generation, thereby killing metastatic cells

October 17, 2017
Cancer can most often be successfully treated when confined to one organ. But a greater challenge lies in treating cancer that has metastasized, or spread, from the primary tumor throughout the patient's body. Although immunotherapy ...

Gut response to fluid flow

October 27, 2017
Flow of fluids through the gut, such as milk from an infant's diet, generates a shear stress on cells lining the intestine. Ken Lau, Ph.D., and colleagues have demonstrated that microvilli – finger-like membrane protrusions ...

Recommended for you

Estrogen discovery could shed new light on fertility problems

December 12, 2017
Estrogen produced in the brain is necessary for ovulation in monkeys, according to researchers at the University of Wisconsin-Madison who have upended the traditional understanding of the hormonal cascade that leads to release ...

Time of day affects severity of autoimmune disease

December 12, 2017
Insights into how the body clock and time of day influence immune responses are revealed today in a study published in leading international journal Nature Communications. Understanding the effect of the interplay between ...

3-D printed microfibers could provide structure for artificially grown body parts

December 12, 2017
Much as a frame provides structural support for a house and the chassis provides strength and shape for a car, a team of Penn State engineers believe they have a way to create the structural framework for growing living tissue ...

Team identifies DNA element that may cause rare movement disorder

December 11, 2017
A team of Massachusetts General Hospital (MGH) researchers has identified a specific genetic change that may be the cause of a rare but severe neurological disorder called X-linked dystonia parkinsonism (XDP). Occurring only ...

Protein Daple coordinates single-cell and organ-wide directionality in the inner ear

December 11, 2017
Humans inherited the capacity to hear sounds thanks to structures that evolved millions of years ago. Sensory "hair cells" in the inner ear have the amazing ability to convert sound waves into electrical signals and transmit ...

Gene therapy improves immunity in babies with 'bubble boy' disease

December 9, 2017
Early evidence suggests that gene therapy developed at St. Jude Children's Research Hospital will lead to broad protection for infants with the devastating immune disorder X-linked severe combined immunodeficiency disorder. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.