PMID: 9334252

 

    Legend: Gene, Sites

Title : C-Mannosylation of human RNase 2 is an intracellular process performed by a variety of cultured cells

Abstract :
  1. C2-alpha-Mannosyltryptophan was discovered in RNase 2 from human urine, representing a novel way of attaching carbohydrate to a protein
  2. Here, we have addressed two questions related to the biosynthesis of this modification: (i) is C-mannosylation part of the normal intracellular biosynthetic route, and (ii) how general is it, i.e. which organisms perform this kind of glycosylation
  3. To answer the first question, RNase 2 , which is identical to the eosinophil-derived neurotoxin , was isolated from intracellular stores of cultured human HL-60 cells
  4. The enzyme was C-mannosylated at Trp-7 , showing that the modification occurs intracellularly, before secretion of the protein
  5. The second question was investigated by immunological and chemical analysis of RNase 2 purified from the supernatant of transiently transformed cells from different organisms
  6. This revealed that C-mannosylation occurs in cells from man, green monkey, pig, mouse, and hamster
  7. The observation that pig kidney cells contain the machinery for C-mannosylation of Trp-7 of human RNase 2 but that the homologous RNase from porcine kidney is not a substrate, since it does not contain a tryptophan at position 7 , strongly suggests that C-mannosylated proteins other than RNase 2 exist
  8. Recombinant RNase 2 isolated from insect cells, plant protoplasts, and Escherichia coli was not C-mannosylated
  9. These results not only form the basis for further studies on the biochemical aspects of C-mannosylation but also have implications for the choice of cells for production of recombinant glycoproteins
Output (sent_index, trigger, protein, sugar, site):
  • 0. RNase, , RNase 2, C-Mannosylation, -
  • 1. urine, , RNase 2, urine, -
  • 4. C-mannosylated, , -, C-mannosylated, Trp-7
  • 4. C-mannosylated, , enzyme, -, Trp-7
  • 4. C-mannosylated, , enzyme, C-mannosylated, -
  • 4. Trp-7, , -, C-mannosylated, Trp-7
  • 7. C-mannosylated, , -, C-mannosylated proteins, -
  • 7. C-mannosylation, , -, -, Trp-7
  • 8. C-mannosylated, , Recombinant RNase 2, -, -
  • 9. glycoproteins, , glycoproteins, -, -
Output(Part-Of) (sent_index, protein, site):
  • 4. enzyme, Trp-7
  • 7. RNase 2, Trp-7
*Output_Site_Fusion* (sent_index, protein, sugar, site):
  • 4. RNase 2, C-mannosylated, Trp-7
  • 4. enzyme, -, Trp-7
  • 7. RNase 2, -, Trp-7

 

 

Protein NCBI ID SENTENCE INDEX
RNase 2 6036 0,1,3,5,7
Recombinant RNase 2 6036 8