title: Fungal phosphate transporter serves as a receptor backbone for gibbon ape leukemia virus.
abstract: Pit1, the receptor for gibbon ape leukemia virus (GALV), is proposed to be an integral membrane protein with five extracellular loops. Chimeras made between Pit1 homologs differing in permissivity for infection and between Pit1 and the related protein Pit2 have shown that the fourth extracellular loop plays a critical role in infection. However, further elucidation of the roles of the extracellular loops in infection is hampered by the high level of sequence similarity among these proteins. The sodium-dependent phosphate transporter, Pho-4, from the filamentous fungus Neurospora crassa is distantly related to Pit1 and -2, showing an amino acid identity of only 35% to Pit1 in the putative extracellular loops. We show here that Pho-4 itself does not function as a receptor for GALV. Introduction of 12 Pit1-specific amino acid residues in the putative fourth extracellular loop of Pho-4 resulted in a functional GALV receptor. Therefore, the presence of a Pit1 loop 4-specific sequence is sufficient to confer receptor function for the mammalian retrovirus GALV on the fungal phosphate transporter Pho-4.
authors.affiliation: Department of Molecular and Structural Biology, University of Aarhus, Aarhus C, Denmark. LP@mbio.aau.dk
authors.forename: L
authors.initials: L
authors.lastname: Pedersen
authors.forename: M
authors.initials: M
authors.lastname: van Zeijl
authors.forename: S V
authors.initials: SV
authors.lastname: Johann
authors.forename: B
authors.initials: B
authors.lastname: O'Hara
mesh_terms: D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D006922:Hylobates; D017989:Leukemia Virus, Gibbon Ape / Q000502:physiology*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009492:Neurospora crassa / Q000378:metabolism; D028061:Phosphate Transport Proteins; D014176:Protein Biosynthesis; D011991:Receptors, Virus / Q000737:chemistry / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D026901:Membrane Transport Proteins; D028061:Phosphate Transport Proteins; D011991:Receptors, Virus; D011993:Recombinant Fusion Proteins; C067981:leukemia virus receptor, gibbon ape; C055831:phosphate permease