Developmental Increase in Ecto-5'-Nucleotidase Activity Overlaps with Appearance of Two Immunologically Distinct Enzyme Isoforms in Rat Hippocampal Synaptic Plasma Membranes
2014
Аутори:
Grkovic, IvanaBjelobaba, Ivana
Nedeljkovic, Nadezda
Mitrovic, Natasa
Drakulic, Dunja
Stanojlovic, Milos
Horvat, Anica
Тип документа:
Чланак у часопису (Објављена верзија)
Метаподаци
Приказ свих података о документуАпстракт:
Ecto-5'-nucleotidase (e-5NT), a glycosylphosphatidylinositol-linked
membrane protein, catalyzes a conversion of AMP to adenosine, which
influences nearly every aspect of brain physiology, including embryonic
and postnatal brain development. The present study aimed to investigate
a pattern of expression, activity and kinetic properties of e-5NT in the
hippocampal formation and synaptic plasma membrane (SPM) preparations in
rats at postnatal days (PDs) 7, 15, 20, 30 and 90. By combining gene
expression analysis and enzyme histochemistry, we observed that e-5NT
mRNA reached the adult level at PD20, while the enzyme activity
continued to increase beyond this age. Further analysis revealed that
hippocampal layers rich in synapses expressed the highest levels of
e-5NT activity, while in layers populated with neuronal cell bodies, the
enzyme activity was weak or absent. Therefore, activity and expression
of e-5NT were analyzed in SPM preparations isolated from rats at
different ages. The presence of two protein bands of about 65 and 68 kDa
was determined by immunoblot analysis. The 65-kDa band was present at
all ages, and its abundance increased from PD7 to PD20. The 68-kDa band
appeared at PD15 and increased until PD30, coinciding with the increase
of e-5NT activity, substrate affinity and enzymatic efficiency. Since
distinct e-5NT isoforms may derive from different patterns of the enzyme
protein N-glycosylation, we speculate that long-term regulation of e-5NT
activity in adulthood may be effectuated at posttranslational level and
without overall change in the gene and protein expression.
Кључне речи:
Ecto-5 `-nucleotidase; Adenosine; Synaptic plasma membranes; Hippocampus; Development; PlasticityИзвор:
Journal of Molecular Neuroscience, 2014, 54, 1, 109-118
DOI: 10.1007/s12031-014-0256-0
ISSN: 1559-1166