Multidrug Resistance-associated Protein 9 (ABCC12) is present in mouse and boar sperm

N Ono , I van Der Heijden , G L Scheffer , K van de Wetering , E van Deemter , M de Haas , A Boerke , B M Gadella , D G de Rooij , J J Neefjes , T Am Groothuis , L Oomen , L Brocks , T Ishikawa , P Borst , P Borst (1)

1 Division of Molecular Biology

The human and murine genes for Multidrug Resistance Protein 9 (ABCC12) yield many alternatively spliced RNAs. Using a panel of monoclonal antibodies we detected full-length Mrp9 only in testicular germ cells and mouse sperm; we obtained no evidence for the existence of the truncated 100 kDa MRP9 protein previously reported. In contrast to other MRPs, neither murine Mrp9, nor the human MRP9 produced in MRP9-transfected Human Embryonic Kidney 293 (HEK 293) cells appear to contain N-linked carbohydrates. In mouse and boar sperm Mrp9 localizes to the mid-piece, a structure containing all sperm mitochondria. However, immuno-localization microscopy and cell fractionation studies on transfected HEK cells and mouse testis show that MRP9/Mrp9 does not route to mitochondria. In HEK cells it is predominantly localized in the endoplasmic reticulum. We have been unable to demonstrate transport by MRP9 of substrates transported by other MRPs, such as drug conjugates and other organic anions.

Mots clés: Life Sciences

N Ono, I van Der Heijden, G L Scheffer, K van de Wetering, E van Deemter, et al.. Multidrug Resistance-associated Protein 9 (ABCC12) is present in mouse and boar sperm. Biochemical Journal, 2007, 406 (1), pp.31-40. ⟨10.1042/BJ20070292⟩. ⟨hal-00478766⟩