GLVR1, a receptor for gibbon ape leukemia virus, is homologous to a phosphate permease of Neurospora crassa and is expressed at high levels in the brain and thymus

Abstract

The human gene GLVR1 has been shown to render mouse cells sensitive to infection by gibbon ape leukemia virus. This indication that the GLVR1 protein acts as a virus receptor does not reveal the protein's normal physiological role. We now report that GLVR1 is homologous to pho-4', a phosphate permease of Neurospora crassa, at a level sufficiently high to predict that GLVR1 is also a transport protein, although the substrate transported remains unknown. To characterize the gene further, we have cloned cDNA for the mouse homolog of the gene, Glvr-1. The sequence of the murine protein differs from that of the human protein in 10% of residues, and it may be presumed that some of these differences are responsible for the inability of gibbon ape leukemia virus to infect mouse fibroblasts. Glvr-l RNA is most abundant in mouse brain and thymus, although it is present in all tissues examined. The pattern of RNA expression found in mouse tissues was also found in rat tissues, in which the RNA was expressed at high levels in all compartments of the brain except the caudate nucleus and was expressed most abundantly early in embryogenesis. Thus, high-level expression of Glvr-l appears to be restricted to specific tissues and may have developmental consequences.

Evolutionary and experimental analyses of inorganic phosphate transporter PiT family reveals two related signature sequences harboring highly conserved aspartic acids critical for sodium‐dependent phosphate transport function of human PiT2

“…In 2002 Farrell et al proposed a PiT1 membrane topology model, which is based primarily on TM predictions by PHD but also leans on PiT2 glycosylation data obtained by Salau¨n and coworkers [41]. For the N-terminal three-fourths of PiT2 (residues 1-483) and PiT1 (residues 1-511) the topological models suggested by both groups comprise seven N-terminal TM domains (I to VII) preceding the large intracellular domain (TM IV was not predicted by Johann et al [22]) ( Fig. 7).…”

“…The spatial [41]. The numbering of the corresponding TM regions predicted by Johann et al [22] is shown in parentheses (TM1-TM10; N.P., not predicted); the N-and C-terminal ends were predicted to be intracellular in this model. The TMs predicted by Johann et al [22], Salaü n et al [23], Farrell et al [41], and PHD at the PredictProtein Server (data not shown) differ in their exact positions.…”

“…The numbering of the corresponding TM regions predicted by Johann et al [22] is shown in parentheses (TM1-TM10; N.P., not predicted); the N-and C-terminal ends were predicted to be intracellular in this model. The TMs predicted by Johann et al [22], Salaü n et al [23], Farrell et al [41], and PHD at the PredictProtein Server (data not shown) differ in their exact positions. The presence of a large intracellular hydrophobic domain in the middle of the proteins is common for all models and was confirmed by immunocytochemistry on PiT2 [67].…”

Human Immunodeficiency Virus Type 1-Associated Cd4 Downmodulation

“…Gibbon ape leukemia virus (GALV) and the closely related simian sarcoma associated virus (SSAV), as well as feline leukemia virus subgroup B (FeLV-B) cross-interfere with one another and belong to receptor group 5. The gene that encodes this receptor, termed GLVRl, has been isolated and shown to resemble a phosphate permease (Johann et al, 1992;O'Hara et al, 1990;Takeuchi et al, 1992) (Table I).…”

“…On the basis of these criteria, three retroviral receptors have been identified and include the well-characterized CD4 molecule, for human immunodeficiency viruses types 1 and 2 (HIV-1 and HIV-2) and simian immunodeficiency viruses (SIVs) Dalgleish et al, 1984;Klatzmann et al, 1984;Maddon et al, 1986;; a basic amino acid transporter termed ecoR or Rec-1, which serves as a specific receptor for the ecotropic murine leukemia viruses (MuLV-E) (Albritton etal., 1989;Kim etal., 1991;Wang etal., 1991a,b); and the GLVRl gene product, which serves as a receptor for gibbon ape leukemia virus (GALV) (O'Hara et al, 1990), the homologous simian sarcoma-associated virus (SSAV), and feline leukemia virus subgroup B (FeLV-B) (Takeuchi et al, 1992). GLVRl also shares homology with a phosphate permease of Neurosporu c r a~~a (Johann et al, 1992).…”