Energy Regulation: Key Protein Identified

A key protein in energy regulation has been identified in a new research by scientists at the Gladstone Institute of Virology and Immunology.

Eric Verdin, senior investigator and senior author of the study, said: "Many mitochondrial proteins undergo a small chemical modification known as acetylation, which varies during feeding and fasting conditions.

Protein Atf4 Found to Regulate Bone-cell Control of Energy Generation
It has come to light very recently that bone cells known as osteoblasts have a role in controlling the biochemical reactions that generate energy via secretion of the molecule osteocalcin.

"From our previous studies, we knew that the enzyme SIRT3 is involved in removing these modifications, and we speculated that SIRT3 might have a role in regulating metabolism and looked for how it might do this."

To investigate the enzyme's role in mice, the scientists used mice in which both copies of the gene had been deleted. It was seen that mice that lost both copies of the SIRT3 gene appeared to be completely normal. However, the researchers then tested the mice under fasting conditions. During fasting, expression of SIRT3 was increased in the liver, an organ that helps maintain the body's energy balance. The livers of mice without SIRT3 had higher levels of fat and triglycerides than normal mice, because the mice could not burn fat.

To find out how SIRT3 controls fat burning, the team looked at the mitochondrial proteins. They found that the enzyme called LCAD was "hyperacetylated" and contained even more acetyl groups than usual and the enzyme had reduced activity.

Cardiovascular Disease may be Treated by Shifting Cellular Energy Metabolism
A range of conditions including heart attack and stroke may be treated by drugs that target the way cells convert nutrients into energy.

The mice that did not have SIRT3 also had many of the key markers of fat oxidation disorders, low energy levels and low tolerance to cold. Further analysis showed that higher levels of SIRT3 expression and activity increase the activity of this key enzyme in fat oxidation. However, a number of other proteins are acetylated in the mitochondria, an observation which suggests that other proteins may be involved.

Matthew Hirschey, postdoctoral fellow and lead author of the study, said: "We conclude that acetylation is a new mechanism for regulating fatty acid oxidation in mitochondria and that SIRT3 mediates the acetylation state.

Energy Drain Makes Most Britons to Say No to Sex: Poll
Britons are so lazy that one in six cannot be bothered to change television channel if the remote control is not working, according to a study published on Monday.

"The implication is that SIRT3 may have a pathologic role in some metabolic disorders, such as diabetes, cardiovascular disease, or fatty liver disease. We are excited about exploring these possibilities."

The study has appeared in the journal Nature.

Source-ANI
TRI