PMID: 2514791

 

    Legend: Gene, Sites

Title : Cell-type-specific and site-specific N-glycosylation of type I and type II human tissue plasminogen activator

Abstract :
  1. Tissue plasminogen activator ( t-PA ) is an important initiator of fibrinolysis
  2. The t-PA polypeptide has four potential N-glycosylation sites of which three are occupied in type I ( Asn-117, -184, and -448 ) and two in type II ( Asn-117 and -448 )
  3. In an effort to elucidate the factors controlling the expression of N-linked oligosaccharides on this polypeptide, we have used a combination of sequential exoglycosidase digestion, methylation analysis, and controlled acetolysis to determine the oligosaccharide structures at each of the N-glycosylation sites of type I and type II t-PA when isolated from a human colon fibroblast cell strain and from a Bowes melanoma cell line
  4. Our results suggest the following: (i) type I and type II t-PA are N-glycosylated in an identical way at Asn-117 and Asn-448, when isolated from the same cell line; (ii) Asn-117 is predominantly associated with oligomannose-type structures in all cases; (iii) Asn-184 and Asn-448 are predominantly associated with complex-type structures when t-PA is isolated from fibroblast cells, but with both complex- and oligomannose-type structures when isolated from melanoma cells; (iv) fibroblast cell derived t-PA is associated with both neutral and sialylated oligosaccharides, while melanoma cell derived t-PA is also associated with sulfated oligosaccharides, which are located exclusively at Asn-448 of type II t-PA ; (v) no complex-type structures occur in common between t-PA from the two cell lines
  5. These results indicate that the t-PA glycoprotein is secreted by each cell line as a set of glycoforms, each glycoform being unique with respect to the nature and dis position of oligosaccharides on a common polypeptide
  6. Further, the two cell lines express no glycoform in common, despite expressing the same t-PA polypeptide
  7. The implications of these results for both the control of oligosaccharide processing in different cell lines and the genetic engineering of mammalian glycoproteins are discussed
Output (sent_index, trigger, protein, sugar, site):
  • 2. I, , -, -, Asn-117, -184, and -448
  • 2. N-glycosylation, , -, -, sites
  • 2. two, , -, -, Asn-117 and -448
  • 3. N-glycosylation, , -, -, sites
  • 4. N-glycosylated, , -, (i) type I, -
  • 4. N-glycosylated, , -, an identical way, -
  • 4. N-glycosylated, , -, the following: (i) type I and type II t-PA are N-glycosylated in an identical way at Asn-117 and Asn-448, when isolated from the same cell line; (ii) Asn-117 is predominantly associated with oligomannose-type structures in all cases; (iii) Asn-184, -
  • 4. N-glycosylated, , -, type II t-PA, -
  • 4. located, , -, sulfated oligosaccharides, Asn-448
  • 4. sialylated, , -, both neutral and sialylated oligosaccharides, -
  • 5. glycoprotein, , t-PA glycoprotein, -, -
  • 5. oligosaccharides, , -, a common polypeptide, polypeptide
  • 7. glycoproteins, , glycoproteins, -, -
Output(Part-Of) (sent_index, protein, site):
  • 2. t-PA, polypeptide
  • 4. II t-PA, Asn-448
  • 6. t-PA, polypeptide
*Output_Site_Fusion* (sent_index, protein, sugar, site):
  • 2. tissue plasminogen activator, -, Asn-117 and -448
  • 2. tissue plasminogen activator, -, Asn-117, -184, and -448
  • 4. II t-PA, sulfated oligosaccharides, Asn-448

 

 

Protein NCBI ID SENTENCE INDEX