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Differentiation‐Dependent Sialylation of Individual Neural Cell Adhesion Molecule Polypeptides During Postnatal Development
Author(s) -
Breen Kieran C.,
Regan Ciaran M.
Publication year - 1988
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1988.tb02972.x
Subject(s) - sialic acid , neural cell adhesion molecule , golgi apparatus , cell adhesion molecule , embryonic stem cell , adhesion , cell adhesion , sialyltransferase , microbiology and biotechnology , biology , biochemistry , chemistry , n acetylneuraminic acid , cell , gene , organic chemistry
The postnatal sialylation of individual neural cell adhesion molecule (N‐CAM) polypeptides by a develop‐mentally regulated sialyltransferase in Golgi‐enriched fractions isolated from rat brain is described. The 120‐kilodal‐ton polypeptide of N‐CAM was found to be sialylated at each developmental age examined. This was in contrast to the 140‐ and 180‐kilodalton N‐CAM polypeptides which were only sialylated until postnatal day 10 and from postnatal day 12, respectively. Immunoblotting procedures demonstrated that all N‐CAM polypeptides were expressed in the Golgi fractions at each developmental stage examined. The heavily sialylated “embryonic” form of N‐CAM was found to be reexpressed at postnatal days 10 and 12, a time coincident with extensive fibre outgrowth. The “embryonic” form of N‐CAM incorporated similar amounts of [ 14 C]sialic acid into its constituent polypeptides reflecting the difference in sialic acid to protein ratio, as this form of N‐CAM was virtually undetectable in the immunoblots of postnatal material.