Neuroprotection may prevent or forestall the progression of incurable eye diseases, such as retinitis pigmentosa, one of the major causes of adult blindness. Decreased cellular ATP levels may contribute to the pathology of this eye disease and other neurodegenerative diseases. Here we describe small compounds (Kyoto University Substances, KUSs) that were developed to inhibit the ATPase activity of VCP (valosin-containing protein), the most abundant soluble ATPase in the cell. Surprisingly, KUSs did not significantly impair reported cellular functions of VCP but nonetheless suppressed the VCP-dependent decrease of cellular ATP levels. Moreover, KUSs, as well as exogenous ATP or ATP-producing compounds, e.g. methylpyruvate, suppressed endoplasmic reticulum stress, and demonstrably protected various types of cultured cells from death, including several types of retinal neuronal cells. We then examined their in vivo efficacies in rd10, a mouse model of retinitis pigmentosa. KUSs prevented photoreceptor cell death and preserved visual function. These results reveal an unexpected, crucial role of ATP consumption by VCP in determining cell fate in this pathological context, and point to a promising new neuroprotective strategy for currently incurable retinitis pigmentosa.

Valosin-containing protein (p97/VCP) has been proposed as playing crucial roles in a variety of physiological and pathological processes such as cancer and neurodegeneration. We previously showed that VCP(K524A), an ATPase activity-negative VCP mutant, induced vacuolization, accumulation of ubiquitinated proteins, and cell death, phenotypes commonly observed in neurodegenerative disorders. However, any regulatory mechanism of its ATPase activity has not yet been clarified. Here, we show that oxidative stress readily inactivates VCP ATPase activity. With liquid chromatography/tandem mass spectrometry, we found that at least three cysteine residues were modified by oxidative stress. Of them, the 522nd cysteine (Cys-522) was identified as the site responsible for the oxidative inactivation of VCP. VCP(C522T), a single-amino acid substitution mutant from cysteine to threonine, conferred almost complete resistance to the oxidative inactivation. In response to oxidative stress, VCP strengthened the interaction with Npl4 and Ufd1, both of which are essential in endoplasmic reticulum-associated protein degradation. Cys-522 is located in the second ATP binding motif and is highly conserved in multicellular but not unicellular organisms. Cdc48p (yeast VCP) has threonine in the corresponding amino acid, and it showed resistance to the oxidative inactivation in vitro. Furthermore, a yeast mutant (⌬cdc48 ؉ cdc48[T532C]) was shown to be susceptible to oxidants-induced growth inhibition and cell death. These results clearly demonstrate that VCP ATPase activity is regulated by the oxidative modification of the Cys-522 residue. This regulatory mechanism may play a key role in the conversion of oxidative stress to endoplasmic reticulum stress response in multicellular organisms and also in the pathological process of various neurodegenerative disorders.

p97/valosin-containing protein (VCP) is a member of the AAA family proteins, which plays various important roles in cells by using its ATPase activity. But mechanism of regulating its ATPase activity is mostly unknown. We report here that VCP is highly modified throughout the protein via acetylation and phosphorylation. In addition to six previously identified phosphorylation sites, we identified at least 14 serines, 14 threonines, 6 tyrosines and 22 lysines as potential modification sites.

Abnormal protein accumulation is often observed in human neurodegenerative disorders such as polyglutamine diseases and Parkinson disease. Genetic and biochemical analyses indicate that valosin-containing protein (VCP) is a crucial molecule in the pathogenesis of human neurodegenerative disorders. We report here that VCP was specifically modified in neuronal cells with abnormal protein accumulation; this modification caused the translocation of VCP into the nucleus. Modification-mimic forms of VCP induced transcriptional suppression with deacetylation of core histones, leading to cell atrophy and the decrease of de novo protein synthesis. Preventing VCP nuclear translocation in polyglutamine-expressing neuronal cells and Drosophila eyes mitigated neurite retraction and eye degenerations, respectively, concomitant with the recovery of core histone acetylation. This represents a novel feedback mechanism that regulates abnormal protein levels in the cytoplasm during physiological processes, as well as in pathological conditions such as abnormal protein accumulation in neurodegenerations.

Abstruct Data Envelopment Analysis (DEA) is a rnathematical programming approach to assess relative eficiencies with a greup ef decision making units (DMUs) such as prQduction systerrB. There have been some llsefu1 models for their successfu1 applications in many fields. In this paper, we first point ou,t the defect of the first DEA model CCR (Charnes, Cooper and Rhodes, 1978) in measuring the eficiencies ef the production systern with le independent subsystexns and propose a new mode] YMK CYang, Ma and Koike) by improving CCR model. Seme properties and the relationship between CCR and YMK models aJre also discussed. It is concluded that the overall eficiency (YMK) of each DMU has a great deal to do with the eficiencies of its subsystems under CCR modet. In fact, the overal1 efieiency value (YMK) of each DMU is equal to the maximum among the eficiency values of all it,s subsystems u)der CCR model. The examples given dernonstrate the effectiveness of YMK model in rneasuring eficiencies of the producLi,en systerr], with k independent subsystems.