Biosynthesis of the D2 cell adhesion molecule: pulse-chase studies in cultured fetal rat neuronal cells
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Biosynthesis of the D2 cell adhesion molecule: pulse-chase studies in cultured fetal rat neuronal cells. / Lyles, J M; Norrild, B; Bock, E.
I: Journal of Cell Biology, Bind 98, Nr. 6, 1984, s. 2077-81.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Biosynthesis of the D2 cell adhesion molecule: pulse-chase studies in cultured fetal rat neuronal cells
AU - Lyles, J M
AU - Norrild, B
AU - Bock, E
N1 - Keywords: Animals; Antigens; Brain; Carbon Radioisotopes; Cell Adhesion Molecules; Cells, Cultured; Fetus; Fucose; Glucosamine; Hexosamines; Kinetics; Molecular Weight; Neurons; Rats; Tritium; Tunicamycin
PY - 1984
Y1 - 1984
N2 - D2 is a membrane glycoprotein that is believed to function as a cell adhesion molecule (CAM) in neural cells. We have examined its biosynthesis in cultured fetal rat brain neurones. We found D2-CAM to be synthesized initially as two polypeptides: Mr 186,000 (A) and Mr 136,000 (B). With increasing chase times the Mr of both molecules increased to 187,000-201,000 (A) and 137,000-158,000 (B). These were similar to the sizes of D2-CAM labeled with [14C]glucosamine, [3H]fucose and [14C]mannosamine, indicating that the higher Mr species are glycoproteins. In the presence of tunicamycin, which specifically blocks the synthesis of high mannose cores, Mr were reduced to 175,000 (A) and 124,000 (B). Newly synthesized A and B are susceptible to degradation by endo-beta-N-acetyl-glucosaminidase H, which specifically degrades high mannose cores, but they are resistant to such degradation after 150 min of posttranslational processing. Hence, we deduce that A and B are initially synthesized with four to five high mannose cores which are later converted into N-linked complex oligosaccharides attached to asparagine residues. However, no shift of [35S]methionine radioactivity between A and B was detected with different pulse or chase times, showing that these molecules are not interconverted. Thus, our data indicate that the neuronal D2-CAM glycoproteins are derived from two mRNAs.
AB - D2 is a membrane glycoprotein that is believed to function as a cell adhesion molecule (CAM) in neural cells. We have examined its biosynthesis in cultured fetal rat brain neurones. We found D2-CAM to be synthesized initially as two polypeptides: Mr 186,000 (A) and Mr 136,000 (B). With increasing chase times the Mr of both molecules increased to 187,000-201,000 (A) and 137,000-158,000 (B). These were similar to the sizes of D2-CAM labeled with [14C]glucosamine, [3H]fucose and [14C]mannosamine, indicating that the higher Mr species are glycoproteins. In the presence of tunicamycin, which specifically blocks the synthesis of high mannose cores, Mr were reduced to 175,000 (A) and 124,000 (B). Newly synthesized A and B are susceptible to degradation by endo-beta-N-acetyl-glucosaminidase H, which specifically degrades high mannose cores, but they are resistant to such degradation after 150 min of posttranslational processing. Hence, we deduce that A and B are initially synthesized with four to five high mannose cores which are later converted into N-linked complex oligosaccharides attached to asparagine residues. However, no shift of [35S]methionine radioactivity between A and B was detected with different pulse or chase times, showing that these molecules are not interconverted. Thus, our data indicate that the neuronal D2-CAM glycoproteins are derived from two mRNAs.
M3 - Journal article
C2 - 6725409
VL - 98
SP - 2077
EP - 2081
JO - Journal of Cell Biology
JF - Journal of Cell Biology
SN - 0021-9525
IS - 6
ER -
ID: 21607312