Cleavage of calnexin caused by apoptotic stimuli: Implication for the regulation of apoptosis

金沢大学医薬保健研究域薬学系Calnexin is an endoplasmic reticulum (ER)-resident molecular chaperone that plays an essential role in the correct folding of membrane proteins. We found that calnexin is subjected to partial cleavage in apoptotic mouse cells. Both ER stress-inducing and ER stress-non-inducing apoptotic stimuli caused the cleavage of calnexin, indicating that this event does not always occur downstream of ER stress. The inhibition of caspases that target the amino acid sequence DXXD abrogated calnexin cleavage in apoptotic stimulus-treated cells. In addition, disruption of one of two DXXD sequences located in the cytoplasmic domain caused calnexin to escape cleavage during apoptosis. Furthermore, calnexin was cleaved in vitro by recombinant caspase-3 or caspase-7. Finally, the overexpression of a presumed cleavage product of calnexin partly inhibited apoptosis. These results collectively suggest that caspase-3 or caspase-7 cleaves calnexin, whose cleaved product leads to the attenuation of apoptosis

Silicon preparation techniques for nucleation and growth studies of zinc sulfide deposited by atomic layer epitaxy.

Zinc sulfide with a direct bandgap of 3.6 eV is a potential candidate as blue-light emitting diodes and lasers. Initial growth of ZnS on Si(100) substrates by atomic layer epitaxy (ALE), a deposition technique in which film growth ideally proceeds in a 2-dimensional, layer-by-layer manner, has been investigated. The interaction between the first layer of atoms of the film and the substrate surface initiates film growth and affects the resulting structure. Work has focused on the effects of surface composition, (particularly on the role of sulfur) on the initial growth of ZnS on Si(100), and thus the chemical composition must be well controlled and characterized. Three methods have been used to process Si(100) substrates. The first was a wet chemical clean with either HF or H₂O passivation followed by a low temperature (700-800°C) anneal in UHV. The second processing method was ion sputter cleaning with a post-sputter anneal at 800-900°C. The third technique irradiated substrates held in UHV with a beam from a KrF excimer laser. Initial layers of ZnS (from Zn and H₂S) were then deposited onto processed substrates. Samples were characterized by in-situ angle resolved x-ray photoelectron spectroscopy (ARXPS) to determine the chemical composition of the surface and also the coverage and thickness of contamination and film layers. The main impurities on the surface were oxygen and carbon. The first two processing techniques had difficulty in either eliminating those impurities or caused additional contamination. Elimination of the impurities was achieved using excimer laser irradiation with a pre-dose of reactive gas. The substrate surface could also be chemically modified in a controlled manner using excimer laser irradiation. Deposition studies of initial sulfur and zinc layers onto the processed substrates determined the temperature during ALE growth should be held at 250-310°C. Uniform coverage of both sulfur and zinc was difficult to obtain, but experiments indicated sulfur adhesion improved with the presence of oxygen, and zinc adhesion improved when oxide or sulfide layers were present on the surface

Evaluation capacity building in college language programs: Developing and sustaining a student exit survey project

Faculty attitudes toward institutionally mandated (or accountability driven) program evaluation demands vary along a continuum of proactive to reactive stances. Such variation is partly related to how individual faculty members perceive the ultimate users and uses of evaluation, as well as the workload associated with evaluation activities. Thus, in order to conduct externally mandated program evaluation successfully, the institution needs to balance the evaluation needs of various stakeholders—both within and beyond departments and programs—and invest in evaluation capacity building that supports faculty evaluation efforts. The purpose of this chapter is to describe the processes and outcomes of a college-level program evaluation initiative, as well as illuminate key issues and challenges in postsecondary program evaluation. Specifically, we discuss how the dean’s office of the College of Languages, Linguistics, and Literature (CLLL) at the University of Hawai‘i at Ma-noa built evaluation capacity to develop and sustain an online student exit survey system. Despite challenges with survey administration and use of data, the initiative has had a number of meaningful, productive outcomes for CLLL faculty. The general impact of the project, we feel, has been an increased capability on the part of CLLL faculty and staff to make evidence-based decisions about program development. This chapter discusses the lessons the college has learned from the exit survey evaluation initiative and makes suggestions for other institutions planning to undertake similar evaluation projects

Pathological changes in levels of three small stress proteins, αB crystallin, HSP 27 and P20, in the hindlimb muscles of dy mouse

AbstractUsing three different analyses, we investigated the levels of the three small stress proteins αB crystallin, HSP 27 and p20 in the slow-twitch soleus muscle and fast-twitch tibialis anterior muscle of normal and dy mice. All of these analyses (immunoassay, Western blot and immunohistochemistry) showed markedly increased levels of these stress proteins in fast-twitch type muscle (tibialis anterior muscle) of dy mouse. In contrast, the levels of αB crystallin, HSP 27 and p20 of dy mouse were reduced in slow-twitch type muscle (soleus muscle). Manipulation of this protective response may reduce injury and may have potential therapeutic application in congenital muscular dystrophy (CMD), which possesses a deficiency of laminin-α2 chain in muscle fiber basement similar to dy mouse