A Novel Membrane Protein Is a Mouse Mammary Tumor Virus Receptor

Abstract

Mouse mammary tumor virus (MMTV) infects a number of different cell types, including mammary gland and lymphoid cells, in vivo. To identify the cellular receptor for this virus, a mouse cDNA expression library was transfected into Cos-7 monkey kidney cells, and those transfected cells able to bind virus were selected by using antibody against the virus’s cell surface envelope protein, gp52. One clone isolated from a library prepared from newborn thymus RNA, called MTVR, was able to confer virus binding to both monkey and human cells; this binding was blocked by anti-MTVR antibody. Moreover, transfection of MTVR into CV1 cells rendered them susceptible to infection by a murine leukemia virus-based retrovirus vector pseudotyped with the MMTV envelope protein. An epitope-tagged MTVR cofractionated with cellular membranes. Coimmunoprecipitation of the MMTV envelope protein and a MTVR-rabbit Fc fusion protein showed that these two proteins bound to each other. The MTVR sequence clone is unique, shows no homology to known membrane proteins, and is transcribed in many tissues.

Mouse mammary tumor virus uses mouse but not human transferrin receptor 1 to reach a low pH compartment and infect cells

“…GFP-labeled MMTV Env-pseudotyped MLV recombinant viruses were produced by transient co-transfection of 293T cells with plasmid pENV, pHit111 (murine leukemia virus [MLV] genome with the βgalactosidase marker), pHit60 (MLV gag/pol genes) (Soneoka et al, 1995), and Matrix-GFP (the MLV matrix protein with an in-frame fusion to E-GFP) as previously described (Golovkina et al, 1998). The supernatant was harvested at 48 h post-transfection and concentrated by ultracentrifugation, 25,000 rpm for 2 h in an SW28 rotor at 4°C.…”

Transmission, Evolution, and Endogenization: Lessons Learned from Recent Retroviral Invasions

“…HYAL2 is a GPI-anchored cell surface protein with a low hyaluronidase activity (100). The receptor for MMTV is the single-transmembrane-spanning transferrin receptor 1 (Tfr1 or Tfrc), which provides a major means of iron uptake into blood cells (101,102). Tfr1 is also a cluster of differentiation (CD) cell surface immunomarker (CD71) that serves as a marker of cells of the erythroid lineage.…”

Gene Expression Profile of the Rat Eye Iridocorneal Angle: NEIBank Expressed Sequence Tag Analysis

“…The encoded protein is related to mammary tumor receptor 2 isoform. 36 cDNA gw06g04 (accession number AY569014) had a length of 4391 bp and encoded a conserved protein with a length of 952 amino acids. This protein is a rat homologue of a recently identified postsynaptic membrane protein, calsynthenin-1.…”