Multidrug resistance-associated protein 9 (ABCC12) is present in mouse and boar sperm.
The human and murine genes for MRP9 (multidrug resistance-associated 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 reported previously. In contrast with other MRPs, neither murine Mrp9 nor the human MRP9 produced in MRP9-transfected HEK-293 cells (human embryonic kidney cells) appears to contain N-linked carbohydrates. In mouse and boar sperm, Mrp9 localizes to the midpiece, a structure containing all sperm mitochondria. However, immunolocalization microscopy and cell fractionation studies with transfected HEK-293 cells and mouse testis show that MRP9/Mrp9 does not localize to mitochondria. In HEK-293 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.
Ono
Nobuhito
N
Division of Molecular Biology and Center of Biomedical Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
Van der Heijden
Ingrid
I
Scheffer
George L
GL
Van de Wetering
Koen
K
Van Deemter
Elizabeth
E
De Haas
Marcel
M
Boerke
Arjan
A
Gadella
Bart M
BM
De Rooij
Dirk G
DG
Neefjes
Jacques J
JJ
Groothuis
Tom A M
TA
Oomen
Lauran
L
Brocks
Lenny
L
Ishikawa
Toshihisa
T
Borst
Piet
P
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000906:Antibodies; D002460:Cell Line; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008297:Male; D051379:Mice; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D051381:Rats; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism*; D013552:Swine / Q000378:metabolism*; D013737:Testis / Q000166:cytology; D014018:Tissue Distribution; D014162:Transfection
D018528:ATP-Binding Cassette Transporters; D000906:Antibodies; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C486658:Abcc12 protein, mouse