The stargazer (stg) mutant mouse, having mutation in stargazin, the
calcium channel gamma2 subunit, exhibited several
neurological disorders including spontaneous
absence seizure,
cerebellar ataxia, and head tossing. To understand the molecular pathogenic mechanism of the
absence seizure resulted from the loss of stargazin function, the thalamic
proteomes between control mouse and stg mouse were compared. We identified 12
proteins expressed differentially (> 1.6-fold) by fluorescence two-dimensional difference gel electrophoresis and tandem mass spectrometry. Six of them are involved in basic metabolism including energy metabolism, three in stress response, two in axonal growth regulation, and one in the endoplasmic reticulum processing. All except
mortalin showed decreased level of expression in stg mouse. Two stress-related
proteins, mouse stress induced
phosphoprotein 1 and
peroxiredoxin 6 exhibited reduced levels of expression in stg mouse, while the level of another
stress protein,
mortalin was increased. Analysis of oxidative protein carbonylation in thalamic
proteome of stg mouse showed higher level of carbonylated
proteins in stg mouse than in control mouse. Interestingly, down-regulation of
stress protein mouse stress induced
phosphoprotein 1, metabolic
enzyme isovaleryl-CoA dehydrogenase, and the two in neuronal axon growth,
collapsin response mediator
protein 2 and
fascin homolog 1 coincides with the results of our previous study on
gamma-butyrolactone-induced transient
absence seizure. Our results suggest that the pathogenesis mechanism underlying
absence seizure may involve the molecular events contributed by these
proteins.