title: The amphotropic murine leukemia virus receptor gene encodes a 71-kilodalton protein that is induced by phosphate depletion.
abstract: The amphotropic murine leukemia virus (MuLV) can infect cells from a number of mammals, including humans, via its specific receptor. Basic knowledge of amphotropic MuLV receptor expression is likely to be useful in the development and improvement of gene therapy protocols based on amphotropic-pseudotyped vectors. To investigate the expression of the human receptor for the amphotropic MuLV (GLVR-2, newly termed Pit2), we determined its mRNA levels in several cell lines and found them to vary significantly. Induction of increased levels of mRNA after removal of phosphate from the media was observed in two osteosarcoma cell lines. The increase in GLVR-2 mRNA resulted in a concomitant rise in the levels of a 71-kDa protein specifically recognized by affinity-purified antibodies against GLVR-2. Using these antibodies, we were able to confirm the intracellular topology of the large hydrophilic domain between the proposed sixth and seventh transmembrane domains of the GLVR-2 protein. This assignment is in agreement with the fourth extracellular loop being outside the cell, consistent with the proposal that the fourth extracellular loop of GLVR-2 contains the envelope binding site.
authors.affiliation: Department of Virology and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Chien
authors.forename: J L
authors.initials: JL
authors.lastname: Foster
authors.forename: J L
authors.initials: JL
authors.lastname: Douglas
authors.forename: J V
authors.initials: JV
authors.lastname: Garcia
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism; D002460:Cell Line; D003593:Cytoplasm / Q000648:ultrastructure; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics; D028061:Phosphate Transport Proteins; D010710:Phosphates / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011990:Receptors, Transferrin; D011991:Receptors, Virus / Q000235:genetics* / Q000378:metabolism*; D050608:Sodium-Phosphate Cotransporter Proteins; D050611:Sodium-Phosphate Cotransporter Proteins, Type III; D012995:Solubility; D027981:Symporters
chemical_list: D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; C068126:CD71 antigen; D008565:Membrane Proteins; D028061:Phosphate Transport Proteins; D010710:Phosphates; D012333:RNA, Messenger; D011990:Receptors, Transferrin; D011991:Receptors, Virus; C493589:SLC20A2 protein, human; C493566:Slc20a2 protein, rat; D050608:Sodium-Phosphate Cotransporter Proteins; D050611:Sodium-Phosphate Cotransporter Proteins, Type III; D027981:Symporters