Protein SEC13 homolog

SEC13 (Protein SEC13 homolog) is a 322-amino acid component of the nuclear pore complex and the COPII coat involved in vesicular trafficking from the endoplasmic reticulum (UniProt: P55735). It also functions as a core component of the GATOR2 complex, which activates the amino acid-sensing branch of mTORC1 signaling by inhibiting the GATOR1 subcomplex; SEC13 and its partner SEH1L are required to stabilize GATOR2 (UniProt: P55735).

SEC13 operates at the intersection of protein secretion and nutrient-sensing pathways, two processes relevant to neuronal homeostasis and synaptic function. The protein's dual roles in COPII-mediated export and mTORC1 regulation suggest involvement in both constitutive and stimulus-dependent cellular processes critical for neuronal viability (UniProt: P55735).

SEC13 is down-regulated in Alzheimer's disease brain tissue (mean log2 fold-change −0.22) compared to age-matched controls in a post-mortem proteomics study (Chaparral AD proteomics). This consistent reduction across one fraction in human AD brain suggests potential impairment of either vesicular trafficking or amino acid-sensitive mTORC1 signaling in disease pathology.