New way of protein modification: stearoylation

We learned the prefixes for lipid in Lesson 14-3. They are:

adip(o)-, lip(o)-, pi(o)-, pimel(o)-, stear(o)-, steat(o)-

One of the prefixes, stear(o)- is used in stearic acid. There is a paper on Nature that is related to stearic acid in 2015.

In this paper, the research team discovered that the activity of human transferrin receptor 1 (TFR1) can be affected by stearoylation. The stearoylated TFR1 cannot activate JNK protein so mitochondria will not become fragmented.

Because fragmented mitochondria is poorly functional, stearoylation is actually a good thing in this aspect.

What is stearic acid? Stearic acid is a long-chain fatty acid, with 18 carbons with no double bond. We usually express fatty acid as "C18:0", meaning this fatty acid has 18 carbons with no double bond. The structure of stearic acid can be seen in the picture below:

Stearic acid. Source: wikipedia

Stearoylation is a whole new way of protein modification. We knew phosphorylation, ubiquitination and glycosylation can affect protein activity. But stearoylation is the first time.

To make this story more interesting, the whole discovery was started on a mistake. So making mistakes isn't so bad sometimes, huh?

Reference:

Teleman A.A. et. al., 2015. Regulation of mitochondrial morphology and function by stearoylation of TFR1. Nature. doi:10.1038/nature14601