کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1927305 1536521 2006 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The binding between p67 and eukaryotic initiation factor 2 plays important roles in the protection of eIF2α from phosphorylation by kinases
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
The binding between p67 and eukaryotic initiation factor 2 plays important roles in the protection of eIF2α from phosphorylation by kinases
چکیده انگلیسی

Phosphorylation of the α-subunit of eukaryotic initiation factor 2 is the major regulatory step in the initiation of protein synthesis in mammals. P67, a cellular glycoprotein, protects phosphorylation of eIF2α from kinases. Previously, we reported that the D6/2 mutant of p67 has higher levels of protection of eIF2α phosphorylation (POEP) activity. In this study, we report that the D6/2 mutant and its double mutants containing second-site alanine substitutions at the five conserved amino acid residues (D251, D262, H331, E364, and E459) show increased POEP activity in serum-starved rat tumor hepatoma cells. Serum-restoration to those cells did not abolish their increased POEP activity except the D6/2+H331A double mutant. The latter mutant shows slight inhibition of POEP activity during serum starvation and this inhibition increased significantly during serum restoration. KRC-7 cells constitutively expressing the D6/2 mutant showed slightly decreased levels of PKR phosphorylation and significantly low level of phosphorylation of ERKs 1 and 2. The D6/2 mutant also showed increased binding with eIF2α and eIF2γ and almost similar binding with ERKs 1 and 2 as compared to wild type p67. Altogether, our data demonstrate that the increased binding of the D6/2 mutant with the subunits of eIF2 may be in part the cause for its high POEP activity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volume 452, Issue 2, 15 August 2006, Pages 138–148
نویسندگان
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