GrpE protein homolog 1, mitochondrial

GRPEL1 (GrpE protein homolog 1, mitochondrial) is an essential component of the PAM (presequence translocase-associated motor) complex, which mediates ATP-dependent translocation of transit peptide-containing proteins across the inner mitochondrial membrane into the matrix. The protein functions by regulating nucleotide-dependent binding of mitochondrial HSP70 to substrate proteins, thereby controlling substrate engagement during translocation (UniProt: Q9HAV7).

GRPEL1 is localized to mitochondria and participates in protein import machinery, a process critical for maintaining mitochondrial function and cellular energy metabolism. No disease associations are documented in UniProt for this protein.

GRPEL1 has been curated as relevant to Alzheimer's Disease in the Chaparral Knowledge Platform based on quantitative proteomics evidence. Analysis of post-mortem AD brain tissue across four subcellular fractions (P2, P3, S2, S3) using TMT-labeled mass spectrometry revealed an ambiguous direction of change relative to age-matched controls, with a mean log2 fold-change of −0.24 (Chaparral AD proteomics). The modest magnitude and inconsistency across fractions preclude definitive assignment of a regulatory direction in AD brain.