Cloning and functional characterization of the Anopheles albimanus DMT1/NRAMP homolog: implications in iron metabolism in mosquitoes.
In addition to its wide role in metabolism, iron in insects has been implicated in vitellogenesis and the immune response. The NRAMP family comprises a well-conserved family of divalent cation transporters in metazoans. To gain insight on the role of NRAMP in Anopheles albimanus, we cloned a cDNA encoding a 571-residue protein (AnaNRAMP) with the structural features defining the NRAMP family. AnaNRAMP mRNA induced (59)Fe(2+) incorporation when injected into Xenopus oocytes. Western blot analysis revealed that AnaNRAMP is expressed in the head, midgut and at high levels in Malpighian tubules of unfed female mosquito. Upon blood feeding, AnaNRAMP levels were reduced in the midgut whereas they increased in the Malpighian tubules. Using immuno-localization by transmission electron microscopy, AnaNRAMP was localized in the membrane of the intra-cellular concretions or spherites of the Malpighian tubule principal cells. Taken together, our results suggest an important role of AnaNRAMP in iron transport and indicate a role of the mosquito Malpighian tubule as an important organ for iron homeostasis.
Martínez-Barnetche
Jesús
J
Centro de Investigación sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Av Universidad 655, Col Sta María Ahuacatitlán, CP 62508 Cuernavaca, Morelos, México.
García Solache
Mónica
M
Neri Lecona
Alba
A
Tello López
Angel T
AT
del Carmen Rodríguez
María
M
Gamba
Gerardo
G
Vázquez
Norma
N
Rodríguez
Mario H
MH
Lanz-Mendoza
Humberto
H
D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004064:Digestive System / Q000378:metabolism; D005260:Female; D007501:Iron / Q000378:metabolism*; D008297:Male; D008317:Malpighian Tubules / Q000378:metabolism; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D010802:Phylogeny; D016415:Sequence Alignment; D014981:Xenopus; D000099173:Natural Resistance-associated Macrophage Protein 1
D027682:Cation Transport Proteins; D018076:DNA, Complementary; D007501:Iron; D000099173:Natural Resistance-associated Macrophage Protein 1