Sorting and assembly machinery component 50 homolog

SAMM50 (sorting and assembly machinery component 50 homolog) is a 469-amino-acid mitochondrial protein that plays a crucial role in maintaining mitochondrial cristae structure and assembling respiratory chain complexes. It is specifically required for assembly of TOMM40 into the TOM complex, which mediates protein import across the outer mitochondrial membrane (UniProt: Q9Y512).

SAMM50 localizes to the mitochondria and functions in organellar bioenergetics and protein trafficking. The UniProt record contains no annotated disease associations in its curated database entries (UniProt: Q9Y512).

SAMM50 is relevant to Alzheimer's disease pathology. Chaparral AD proteomics data from post-mortem human brain tissue (TMT-labeled quantification across four subcellular fractions) demonstrates that SAMM50 is consistently downregulated in AD cases compared to age-matched controls, with a mean log2 fold-change of −0.54 (Chaparral AD proteomics). This downregulation suggests impaired mitochondrial function and cristae remodeling may contribute to the bioenergetic dysfunction observed in AD neurodegeneration.