Download Characterization of DREAM isoforms in astrocytes and neurons

Characterization of DREAM isoforms in astrocytes and
neurons
1，2,*
Yan-Ling ZHOU
2
2
, Feng-Bo SUN , Albert Cheung Hoi YU
1
Department of Physiology, Medical School; Wuhan University of Science and
Technology
2
Neuroscience Research Institute; Department of Neurobiology, School of Basic
Medical Sciences; Key Laboratory for Neuroscience, Ministry of Education; Key
Laboratory for Neuroscience, Ministry of Public Health, Peking University.
Corresponding author
E-mail: [email protected]
Abstract: Objective Downstream regulatory element antagonist modulator (DREAM),
2+
as a multifunctional Ca binding protein, binds with specific DNA sequence to
regulate gene expression and with Kv4.2 or presenilins outside the nucleus to
regulate membrane excitability and calcium homeostasis, respectively. Two main
isoforms of DREAM (A and B) were produced by alternative splicing. Our study is to
observe the characterization of DREAM isoforms expression and distribution in
astrocytes and neurons. Methods Expression of DREAM A and B mRNA in primary culture
of neural cells (astrocytes, GABAergic neuron and glutamatergic neuron) was measured
by real time PCR. Subcloned DREAM isoform A or B in pIRES2-EGFP vectors and the
plasmids were transfected into astrocytes to observe their subcellular localization.
Results We found that both DREAM A and B are present in all neural cells studied.
Isoform A was in a higher level in glutamatergic neuron whereas isoform B was in
a higher level in astrocyte. Isoform A showed a diffusible distribution and isoform
B appeared mainly localized in the ER. The mRNA levels of these two isoforms was
measured in these neural cells at different age. We found that isoform A showed the
highest level in older but isoform B showed the highest level in younger cultures.
We confirmed these developmental changes in tissue of cerebral cortex and cerebellum.
Conclusion These data suggested that DREAM A is the major isoforms in mature cells
and can function as transcriptional repressor. DREAM B is mainly localized in ER
and may play a role in the early stage of development. [This work was supported by
National Natural Science Foundation of China (30670644, 30870818), 973 project
(2011CB504400), Beijing Natural Science Foundation (7091004).]
Keywords: astrocyte, neuron, DREAM, isoforms