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Wakata, Yuka; Tokumoto, Mika; Horiguchi, Ryo; Ishikawa, Katsutoshi; Nagahama, Yoshitaka; Tokumoto, Toshinobu

doi:10.1186/1471-2091-5-18

Cited by 7 publications

(2 citation statements)

References 41 publications

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“…It has also been demonstrated that phosphorylation modulated the formation of the 26S proteasome complex and its proteolytic activities [ 38 ]. Changes in the phosphorylation state of proteasome subunits were detected during the cell cycle transition [ 39 , 40 ], development of Alzheimer's disease [ 10 ] and apoptosis of Jurkat T cells [ 41 ]. These changes in phosphorylation were paralleled by changes in the proteolytic activities of proteasomes.…”

Section: Discussionmentioning

confidence: 99%

DNA damage-induced ubiquitylation of proteasome controls its proteolytic activity

et al. 2013

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Stability of proteins is largely controlled by post-translational covalent modifications. Among those, ubiquitylation plays a central role as it marks the proteins for proteasome-dependent degradation. Proteolytic activities of proteasomes are critical for execution of various cellular processes, including DNA damage signaling and repair. However, very little is known about the regulation of proteasomal activity in cells during genotoxic stress. Here we investigated post-translational modifications of the 20S proteasomal subunits upon DNA damage induced by doxorubicin. Using mass-spectrometry, we found novel sites of phosphorylation and ubiquitylation in multiple proteasome subunits upon doxorubicin treatment. Ectopic co-expression of proteasome subunits and tagged ubiquitin confirmed the presence of ubiquitylated forms of PSMA5, PSMA1, PSMA3 and PSMB5 in cells. Moreover, we demonstrated that ubiquitylation in vitro inhibited chymotrypsin-like and caspase-like activities of proteasomes. In vivo, doxorubicin increased the activity of proteasomes, paralleling with attenuation of the overall level of proteasome ubiquitylation. Collectively, our results suggest a novel mechanism whereby the proteolytic activities of proteasomes are dynamically regulated by ubiquitylation upon DNA damage.

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Section: Discussionmentioning

confidence: 99%

DNA damage-induced ubiquitylation of proteasome controls its proteolytic activity

et al. 2013

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“…To observe the inhibitory activity of the anti-20S proteasome antibodies, the pvm was added into a tube containing either anti-20S proteasome antibody (anti-a5 or anti-a7) (Wakata et al 2004) or normal guinea pig serum diluted 1:200 with HBSS, and sperm suspension was then added at 1!10 7 sperm/ml. The effects of 50 mM carbobenzoxyLeu-Leu-Leu-H (MG132, Sigma), a proteasome inhibitor, 50 mM [2S-3S]-trans-epoxysuccinyl-L-leucylamido-3-methylbutane ethyl ester (E64d, Sigma), a cysteine protease inhibitor, or 200 units/ml apyrase (Sigma) that catalyzes the hydrolysis of ATP and ADP on the sperm perforation of the pvm were also tested as described earlier.…”

Section: Sperm Proteasome In Birdsmentioning

confidence: 99%

Sperm proteasome degrades egg envelope glycoprotein ZP1 during fertilization of Japanese quail (Coturnix japonica)

Sasanami¹,

Sugiura²,

Tokumoto³

et al. 2012

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At the time of fertilization, the extracellular matrix surrounding avian oocytes, termed the perivitelline membrane (pvm), is hydrolyzed by a sperm-borne protease, although the actual protease that is responsible for the digestion of the pvm remains to be identified. Here, we show evidence that the ubiquitin-proteasome system is functional in the fertilization of Japanese quail. The activities for the induction of the acrosome reaction and binding to ZP3 as revealed by ligand blotting of purified serum ZP1 are similar to those of pvm ZP1. Western blot analysis of purified ZP1 and ZP3 by the use of the anti-ubiquitin antibody showed that only pvm ZP1 was reactive to the antibody. In vitro penetration assay of the sperm on the pvm indicated that fragments of ZP1 and intact ZP3 were released from the pvm. Western blot analysis using the anti-20S proteasome antibody and ultrastructural analysis showed that immunoreactive proteasome was localized in the acrosomal region of the sperm. Inclusion of specific proteasome inhibitor MG132 in the incubation mixture, or depletion of extracellular ATP by the addition of apyrase, efficiently suppressed the sperm perforation of the pvm. These results demonstrate for the first time that the sperm proteasome is important for fertilization in birds and that the extracellular ubiquitination of ZP1 might occur during its transport via blood circulation.

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Comparative proteome analysis of changes in the 26S proteasome during oocyte maturation in goldfish

2006

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Proteasomes are large, multi-subunit particles that act as the proteolytic machinery for most of the regulated intracellular protein degradation in eukaryotic cells. An alteration of proteasome function may be important for the regulation of the meiotic cell cycle. To study the change at the subunit level of the 26S proteasome during meiotic maturation, we purified 26S proteasomes from immature and mature oocytes of goldfish. Two-dimensional polyacrylamide gel electrophoresis was used to separate proteins. For differential analysis, whole spots of the 26S proteasome from goldfish oocytes were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and database analysis. Four spots that were different (only detected in mature oocyte 265 proteasomes and not in immature ones) and four protein spots that were up- or down-regulated were identified unambiguously. The mature-specific spots were not 26S proteasome components but rather their interacting proteins, and were identified as chaperonin-containing TCP-1 subunits and myosin light chain. Minor spots of three subunits of the 20S core particle and one of the 19S regulatory particle showed meiotic cell cycle-dependent changes. These results demonstrate that modifications of proteasomal subunits and cell cycle phase-dependent interactions of proteins with proteasomes occur during oocyte maturation in goldfish.

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Cited by 7 publications

References 41 publications

DNA damage-induced ubiquitylation of proteasome controls its proteolytic activity

DNA damage-induced ubiquitylation of proteasome controls its proteolytic activity

Sperm proteasome degrades egg envelope glycoprotein ZP1 during fertilization of Japanese quail (Coturnix japonica)

Comparative proteome analysis of changes in the 26S proteasome during oocyte maturation in goldfish

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