(CFTR) channel chloride transport activity. Channel flow double-electrode (CFDE) cells ectopically expressing wild-type CFTR channels were used to test the effect of CFTR chloride transport inhibitors glibenclamide and CFTR(inh)172 and demonstrated a reduction in MT-ND4 expression. Clinical significance MT-ND4 is one of five SNPs associated with age-related macular degeneration (AMD) in Mexican Americans. Leber's hereditary optic neuropathy (LHON) correlates with a mutation in the MT-ND4 gene in multiple families. The mutation at codon 340 results in the elimination of an Sfa NI site by the conversion of a highly conserved arginine to a histidine. This provides a simple diagnostic test by which to identify LHON, a maternally inherited disease that results in optic nerve degeneration and cardiac dysrythmia. Amino acid changes in MT-ND4, MT-ND5 and MT-ATP8 resulting from mutations at the 11994, 8502 and 13,231 bp of mtDNA are significantly correlated in mesial temporal lobe epilepsy (MTLE) patients with hippocampal sclerosis. The 11994 C>T mutation to the MT-ND4 gene results in a Thr to Ile shift at the 412 position. Genome analysis has never been used in MTLE cases and could provide another diagnostic method in the disease. MT-ND4 is downregulated in cystic fibrosis, a disease that results from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) channel. Interactions MT-ND4 has been shown to have 21 binary protein-protein interactions including 15 co-complex interactions. MT-ND4 appears to interact with SP1, ZNF16, CTCF, GRB2, and ATM. References Further reading External links Mass spectrometry characterization of MT-ND4 at COPaKB Proteins Human mitochondrial genes