PMID: 8323299

 

    Legend: Gene, Sites

Title : Assignment of O-glycan attachment sites to the hinge-like regions of human lysosomal membrane glycoproteins lamp-1 and lamp-2

Abstract :

1. The lysosomal membrane glycoproteins lamp-1 and lamp-2 are extensively glycosylated with a variety of different carbohydrate structures of both N-linked and O-linked type
2. In the present paper, we report the localization of O-linked oligosaccharides exclusively to the hinge-like regions of lamp-1 and lamp-2 isolated from human chronic myelogenous leukemia cells
3. In both glycoproteins , the O-glycans appear in clusters
4. In lamp-1 , Thr-171, Thr-172, Ser-179, Ser-181, and Ser-183 were fully glycosylated, whereas Ser-169 was partially glycosylated
5. In lamp-2 , complete glycosylation was found at Ser-167, Thr-168, Thr-172, Thr-175, Thr-176, Thr-182, and Thr-183 , and partial glycosylation at Ser-179 and Thr-181 , and possibly also at Thr-185
6. The amino acid sequences of these O-glycosylation sites are consistent with the previous reports that residues at positions -1 and +3 may influence the glycosylation reaction
7. Circular dichroism and nuclear magnetic resonance spectroscopy was used for the structural characterization of a synthetic peptide corresponding to residues 167 to 190 of lamp-1
8. The results indicated that the proline-rich O-glycan acceptor region does not adopt any typical periodic structure but differs from random-coil structure
9. The circular dichroism spectrum of the peptide is, however, similar to that of porcine submaxillary apomucin
10. A significant conformational variability was observed in this region , presumably due to a slow (on the nuclear magnetic resonance time scale) cis-trans isomerization of several proline residues
11. These results, taken together, strongly suggest that a hinge region does not display any typical ordered structure
12. The presence of O-glycans thus likely protects this region from intralumenal lysosomal proteases

Output (sent_index, trigger, protein, sugar, site):

• 0. glycoproteins, , glycoproteins, -, -
• 0. glycoproteins, , lamp-1, -, -
• 0. glycoproteins, , lamp-2, -, -
• 1. glycoproteins, , glycoproteins, -, -
• 1. glycoproteins, , lamp-1, -, -
• 1. glycoproteins, , lamp-2, -, -
• 1. glycosylated, , glycoproteins, -, -
• 1. glycosylated, , lamp-1, -, -
• 1. glycosylated, , lamp-2, -, -
• 3. glycoproteins, , glycoproteins, -, -
• 4. glycosylated, , -, -, Ser-169
• 4. glycosylated, , -, -, Thr-171, Thr-172, Ser-179, Ser-181, and Ser-183
• 4. glycosylated, , In lamp-1, -, Thr-171, Thr-172, Ser-179, Ser-181, and Ser-183
• 5. glycosylation, , -, -, Ser-179 and Thr-181
• 5. glycosylation, , -, -, Thr-185
• 5. glycosylation, , In lamp-2, -, Ser-179 and Thr-181
• 5. glycosylation, , In lamp-2, -, Thr-185
• 6. O-glycosylation, , -, -, sites
• 8. proline-rich, , -, the proline-rich O-glycan acceptor region, proline

Output(Part-Of) (sent_index, protein, site):

• 0. glycoproteins, regions
• 2. lamp-1, regions
• 2. lamp-2, regions
• 7. lamp-1, residues 167

*Output_Site_Fusion* (sent_index, protein, sugar, site):

• 4. In lamp-1, -, Ser-169
• 4. In lamp-1, -, Thr-171, Thr-172, Ser-179, Ser-181, and Ser-183
• 5. In lamp-2, -, Ser-179 and Thr-181
• 5. In lamp-2, -, Thr-185

 

Protein	NCBI ID	SENTENCE INDEX
lamp-2	3920	0,1,2
lamp-1	3916	0,1,2,7
In lamp-1	3916	4
In lamp-2	3920	5