کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10804668 | 1057303 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Non-catalytic domains of subunit A negatively regulate the activity of calcineurin
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موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Non-catalytic domains of subunit A negatively regulate the activity of calcineurin Non-catalytic domains of subunit A negatively regulate the activity of calcineurin](/preview/png/10804668.png)
چکیده انگلیسی
Calcineurin is composed of a catalytic subunit A (CNA) and a regulatory subunit B (CNB). In addition to the catalytic core, CNA further contains three non-catalytic domains-CNB binding domain (BBH), calmodulin binding domain (CBD), and autoinhibitory domain (AI). To investigate the effect of these three domains on the activity of CNA, we have constructed domain deletion mutants CNAa (catalytic domain only), CNAac (CNAa and CBD), and CNAaci (CNAa, CBD and AI). By using p-nitrophenylphosphate and 32P-labeled RII peptide as substrates, we have systematically examined the phosphatase activities, kinetics, and regulatory effects of Mn2+/Ni2+ and Mg2+. The results show that the catalytic core has the highest activity and the order of activity of the remaining constructs is CNAac>CNAaci>CNA. Sequential removal of the non-catalytic domains corresponds to concurrent increases of the phosphatase activity assayed under several conditions. This observation clearly demonstrates that non-catalytic domains negatively regulate the enzyme activity and act as intra-molecular inhibitors, possibly through restraining the conformation elasticity of the catalytic core required for optimal catalysis or interfering with substrate access. The sequential domain deletion favors activation of the enzyme by Mn2+/Ni2+ but not by Mg2+ (except for CNAa), suggesting that enzyme activation by Mn2+/Ni2+ is mainly mediated via the catalytic domain, whereas activation by Mg2+ is via both the catalytic core and non-catalytic domains.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimie - Volume 87, Issue 2, February 2005, Pages 215-221
Journal: Biochimie - Volume 87, Issue 2, February 2005, Pages 215-221
نویسندگان
Ping Liu, Chao Huang, Zongchao Jia, Fang Yi, Da-yu Yu, Qun Wei,