feline leukemia virus subgroup C receptor-related protein 1 (feline leukemia virus subgroup C receptor, hFLVCR, FLVCR1, FLVCR)

Function

• isoform 1:
  • exports cytoplasmic heme
    • protection of developing erythroid cells from heme toxicity (putative)
  • required during erythtopoiesis to maintain intracellular free heme balance since in proerythroblasts, heme synthesis intensifies & it's accumulation is toxic for cells
    • protection from heme or Fe+2 toxicities in liver & brain
  • exports coproporphyrin & protoporphyrin IX, both intermediates in the heme biosynthesis
  • does not export bilirubin
  • susceptibility to FeLV-C in vitro
• isoform 2
  • heme transporter that promotes heme efflux from the mitochondrion to the cytoplasm
  • essential for erythroid differentiation
  • interacts with HPX

Structure

• isoform 2 is N-glycosylated
• belongs to the major facilitator superfamily, Feline leukemia virus subgroup C receptor (TC 2.A.1.28.1) family

Compartment

• multi-pass membrane protein
• isoform 1: cell membrane
• isoform 2: mitochondrial membrane

Alternative splicing

• named isoforms=2
• probable mitochondrial transit peptide at positions 1-38

Expression

• expressed in all hematopoietic tissues including: peripheral blood lymphocytes, fetal liver > pancreas, kidney
• down-regulated in hemopoietic progenitor cells undergoing differentiation & hemoglobinization

Pathology

• defects in FLVCR1 are the cause of PCARP posterior column ataxia with retinitis pigmentosa

More general terms

• transmembrane 12 protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=28982
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:28982
• OMIM: https://mirror.omim.org/entry/609033
• OMIM: https://mirror.omim.org/entry/609144
• UniProt: http://www.uniprot.org/uniprot/Q9Y5Y0.html