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...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.展开更多
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 pro...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.展开更多
基金supported by the grantfrom the National Natural Science Foundation of China(31571387).
文摘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.
基金This work was supported by the National Natural Science Foundation of China(31571387).
文摘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.
