Hitchhiking in a cell
Molecular movement may hold a key to understanding ALS.
Microscopic RNA molecules sometimes travel up to a metre to get from the nucleus of a nerve cell to its tip, where they’re needed to make a protein.
And they do that by hitchhiking, suggests a research team from the Howard Hughes Medical Institute in the US.
And, they say, it may be this transit that goes awry in people with the neurodegenerative disease amyotrophic lateral sclerosis (ALS).
RNA transportation is a key part of keeping a cell functioning properly. If it isn't distributed correctly, key proteins might not end up in the right places.
In their latest study, the researchers show how an “adaptor protein” called Annexin A11 allows RNA to latch on to lysosomes, which move easily around a cell, thus plugging into a transportation network that would otherwise be inaccessible.
People with ALS often have mutations in the gene for Annexin A11, says Lippincott-Schwartz, and now, it's becoming clear how these mutations affect patients.
"You can think of this paper as defining a new function for lysosomes," she says.