Small but Significant

Comparing the protein composition of tissue samples from patients and control individuals can provide insights into a given disease. Indeed, such studies identified β-amyloid as being the main component of plaques in Alzheimer’s disease patient brains. But tiny proteins of 150 amino acids or fewer have typically, for technical reasons, been left out of such analyses. The importance of these microproteins is starting to be recognised, however, and recent work has led to the discovery of more than a thousand previously uncharacterised brain microproteins, hundreds of which are present at different levels in Alzheimer’s samples versus controls. One such (orange) is pictured within a microglial cell – a type of brain immune cell responsible for clearing protein debris. While characterisation of these microproteins is just beginning, one was found at unusually low levels in Alzheimer’s patient microglia – its absence reducing the cells’ energy production and thus, potentially, their plaque-clearing capability.

Written by Ruth Williams

Ruth Williams

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Ruth is a freelance science journalist based in the US. She's a regular correspondent for The Scientist, and her work has appeared in The Lancet, Nature, Scientific American Mind, BBC Focus and elsewhere. Twitter @rooph

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• Image from work by Brendan Miller and colleagues, Salk Institute
• Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA, USA
• Image originally published as 'Credit must be given to the creator' and use only with the related science coverage
• Research published in Nature Aging, September 2026