排序方式: 共有34条查询结果,搜索用时 15 毫秒
31.
Tobias Wauer Kirby N Swatek Jane L Wagstaff Christina Gladkova Jonathan N Pruneda Martin A Michel Malte Gersch Christopher M Johnson Stefan MV Freund David Komander 《The EMBO journal》2015,34(3):307-325
The protein kinase PINK1 was recently shown to phosphorylate ubiquitin (Ub) on Ser65, and phosphoUb activates the E3 ligase Parkin allosterically. Here, we show that PINK1 can phosphorylate every Ub in Ub chains. Moreover, Ser65 phosphorylation alters Ub structure, generating two conformations in solution. A crystal structure of the major conformation resembles Ub but has altered surface properties. NMR reveals a second phosphoUb conformation in which β5-strand slippage retracts the C-terminal tail by two residues into the Ub core. We further show that phosphoUb has no effect on E1-mediated E2 charging but can affect discharging of E2 enzymes to form polyUb chains. Notably, UBE2R1- (CDC34), UBE2N/UBE2V1- (UBC13/UEV1A), TRAF6- and HOIP-mediated chain assembly is inhibited by phosphoUb. While Lys63-linked poly-phosphoUb is recognized by the TAB2 NZF Ub binding domain (UBD), 10 out of 12 deubiquitinases (DUBs), including USP8, USP15 and USP30, are impaired in hydrolyzing phosphoUb chains. Hence, Ub phosphorylation has repercussions for ubiquitination and deubiquitination cascades beyond Parkin activation and may provide an independent layer of regulation in the Ub system. 相似文献
32.
Optimization of mycophenolic acid production in solid state fermentation using response surface methodology 总被引:7,自引:0,他引:7
A K Sadhukhan MV Ramana Murthy R Ajaya Kumar E V S Mohan G Vandana C Bhar K Venkateswara Rao 《Journal of industrial microbiology & biotechnology》1999,22(1):33-38
Mycophenolic acid (MPA) can be produced in solid state fermentation. An isolate of Penicillium brevi-compactum ATCC 16024 grown on moist wheat bran produced a titre of 425 mg per kg of wheat bran. Central composite rotatable design
and response surface methodology were employed to derive a statistical model for media optimization towards production of
mycophenolic acid. Five levels with a five factorial design were adopted. The correlation coefficient was 0.82, ensuring a
satisfactory adjustment of the model to the experimental values. This statistical design was very effective in improving the
titre of mycophenolic acid up to 3286 mg per kg of wheat bran.
Received 24 July 1998/ Accepted in revised form 4 December 1998 相似文献
33.
From presence to consciousness through virtual reality 总被引:1,自引:0,他引:1
Immersive virtual environments can break the deep, everyday connection between where our senses tell us we are and where we are actually located and whom we are with. The concept of 'presence' refers to the phenomenon of behaving and feeling as if we are in the virtual world created by computer displays. In this article, we argue that presence is worthy of study by neuroscientists, and that it might aid the study of perception and consciousness. 相似文献
34.
Sheila C Rahal Reinaldo S Volpi Carlos R Teixeira Vania MV Machado Guilherme DP Soares Carlos Ramires Neto Kathleen Linn 《BMC veterinary research》2012,8(1):1-5