Cytosolic iron-sulfur assembly component 2A

CIAO2A (cytosolic iron-sulfur assembly component 2A) is a 160-amino acid protein that functions as a component of the cytosolic iron-sulfur protein assembly (CIA) complex (UniProt: Q9H5X1). It mediates the incorporation of iron-sulfur clusters into extramitochondrial Fe/S proteins and specifically matures ACO1 while stabilizing IREB2, thereby linking iron-sulfur protein maturation with cellular iron regulation. CIAO2A may also participate in chromosome segregation through sister chromatid cohesion and can induce apoptosis in collaboration with APAF1.

The protein is expressed in human tissues and its molecular function centers on iron homeostasis and cofactor assembly, processes critical to cellular metabolism and genomic stability. No disease associations are documented in UniProt.

CIAO2A shows increased abundance in Alzheimer's Disease brain tissue relative to age-matched controls. In a post-mortem human AD brain proteomics study using TMT-labeled mass spectrometry across four subcellular fractions (P2, P3, S2, S3), CIAO2A was significantly upregulated with a mean log2 fold-change of 0.43 (Chaparral AD proteomics). This elevation may reflect altered iron metabolism or increased oxidative stress responses in the AD brain.