SP1 protein interacts with three energy-related cellular organelles

  • Feb 5, 2018
  • Hu lab, fundamental research
  • Fundamental Research
  • By Igor Houwat, Jianping Hu

Recently, the Hu lab published a paper detailing how a protein, SP1, helps construct peroxisomes, cellular food processors that break down fatty acids (ie: fats) into smaller chunks so they can be used to produce energy in both humans and plants.

New research, published in the journal Plant Physiology, provides additional evidence that, as a matter of fact, SP1 interacts with three cellular organelles, expand iconchloroplasts, expand iconmitochondria, and expand iconperoxisomes. Together, the trio of organelles are important for generating and managing energy supplies in humans and plants.

“We found the SP1 expand iconprotein to target to these three organelles in the lab plant, Arabidopsis,” says Hu, who is a professor in the MSU-DOE Plant Research Laboratory and the MSU Department of Biology.

“This triple location pattern is exciting and in line with the fact that the human counterpart to SP1 is known to target to both mitochondria and peroxisomes (humans don’t have chloroplasts).”

Judging by its sequence and functional similarity to the human equivalent, Hu thinks it is possible that SP1 plays additional roles we haven’t realized yet.

For example, the human protein (called MAPL) performs many essential functions, like helping with mitochondrial integrity maintenance, antiviral responses, and self-degradation of defective mitochondria, among other roles.

“We have still a lot to learn about SP1 in plants” Hu says. “SP1-like proteins are present in many other types of plants. Our line of research could spur further exploration, including applications for more robust crops that are better at generating energy – in other words, better crop yields.”

Due to the closeness of the human and plant proteins, this also is an instance where plant science might contribute to human medicine. Human peroxisomal disorders are very debilitating, with symptoms including poor growth, neurological dysfunctions, hearing/visual problems, liver disease, just to name a few.


Banner image of an Arabidopsis plant by INRA, Jean WeberCC BY 2.0