Multi-Domain Parallel Computing for Strength Analysis of Whole Aircraft Model

In the Windows XP 64 bit operating system environment, several common PC were used to build a cluster system, establishing the distributed memory parallel (DMP) computing system. A finite element model of whole aircraft with about 260 million degrees of freedom (DOF) was developed using three-node and four-node thin shell element and two-node beam element. With the large commercial finite element software MSC.MARC and employing two kinds of domain decomposition method (DDM) respectively, realized the parallel solving for the static strength analysis of the whole aircraft model, which offered a high cost-effective solution for solving large-scale and complex finite element models.

The molecular chaperone Hsp90α deficiency causes retinal degeneration by disrupting Golgi organization and vesicle transportation in photoreceptors

Heat shock protein 90(Hsp90)is an abundant molecular chaperone with two isoforms,Hsp90α and Hsp90p.Hsp90β deficiency causes embryonic lethality,whereas Hsp90α deficiency causes few abnormities except male sterility.In this paper,we reported that Hsp90α was exclusively expressed in the retina,testis,and brain.Its deficiency caused retinitis pigmentosa(RP),a disease leading to blindness.In Hsp90α-deficient mice,the retina was deteriorated and the outer segment of photoreceptor was deformed.Immunofluorescence staining and electron microscopic analysis revealed disintegrated Golgi and aberrant intersegmental vesicle transportation in Hsp90α-deficient photoreceptors.Proteomic analysis identified microtubule-associated protein IB(MAP1B)as an Hsp90α-associated protein in photoreceptors.Hspcx deficiency increased degradation of MAP1B by inducing its ubiquitination,causing a-tubulin deacetylation and microtubule destabilization.Furthermore,the treatment of wild-type mice with 17-DMAG,an Hsp90 inhibitor of geldanamycin derivative,induced the same retinal degeneration as Hsp90α deficiency.Taken together,the microtubule destabilization could be the underlying reason for Hsp90α deficiency-induced RP.

The molecular chaperone Hsp90 maintains Golgi organization and vesicular trafficking by regulating microtubule stability

Hsp90 is an abundant and special molecular chaperone considered to be the regulator of many transcription factors and signaling kinases. Its high abundance is indicative of its involvement in some more fundamental processes. In this study, we provide evidence that Hsp90 is required for microtubule stabilization, Golgi organization, and vesicular trafficking. We showed that Hsp90 is bound to microtubule-associated protein 4 (MAP4), which is essential for maintaining microtubule acetylation and stabilization. Hsp90 depletion led to the decrease in MAP4, causing microtubule deacetylation and destabilization. Furthermore, in Hsp90-depleted cells, the Golgi apparatus was fragmented and anterograde vesicle trafficking was impaired, with phenotypes similar to those induced by silencing MAP4. These disruptive effects of Hsp90 depletion could be rescued by the expression of exogenous MAP4 or the treatment of trichostatin A that increases microtubule acetylation as well as stability. Thus, microtubule stability is an essential cellular event regulated by Hsp90.