Modulation of prion formation, aggregation, and toxicity by the actin cytoskeleton in yeast.
نویسندگان
چکیده
Self-perpetuating protein aggregates transmit prion diseases in mammals and heritable traits in yeast. De novo prion formation can be induced by transient overproduction of the corresponding prion-forming protein or its prion domain. Here, we demonstrate that the yeast prion protein Sup35 interacts with various proteins of the actin cortical cytoskeleton that are involved in endocytosis. Sup35-derived aggregates, generated in the process of prion induction, are associated with the components of the endocytic/vacuolar pathway. Mutational alterations of the cortical actin cytoskeleton decrease aggregation of overproduced Sup35 and de novo prion induction and increase prion-related toxicity in yeast. Deletion of the gene coding for the actin assembly protein Sla2 is lethal in cells containing the prion isoforms of both Sup35 and Rnq1 proteins simultaneously. Our data are consistent with a model in which cytoskeletal structures provide a scaffold for generation of large aggregates, resembling mammalian aggresomes. These aggregates promote prion formation. Moreover, it appears that the actin cytoskeleton also plays a certain role in counteracting the toxicity of the overproduced potentially aggregating proteins.
منابع مشابه
Disrupting the cortical actin cytoskeleton points to two distinct mechanisms of yeast [PSI+] prion formation
Mammalian and fungal prions arise de novo; however, the mechanism is poorly understood in molecular terms. One strong possibility is that oxidative damage to the non-prion form of a protein may be an important trigger influencing the formation of its heritable prion conformation. We have examined the oxidative stress-induced formation of the yeast [PSI+] prion, which is the altered conformation...
متن کاملI-6: Role of Actin Cytoskeleton during Mouse Sperm Acrosomal Exocytosis
Background: Mammalian sperm must undergo a process termed capacitation to become competent to fertilize an egg. Capacitation renders the sperm competent by priming the cells to undergo a rapid exocytotic event called acrosomal exocytosis that is stimulated by the zona pellucida (ZP) of the egg or progesterone. Over the years, several biochemical events have been associated with the capacitation...
متن کاملModulation of prion-dependent polyglutamine aggregation and toxicity by chaperone proteins in the yeast model.
In yeast, aggregation and toxicity of the expanded polyglutamine fragment of human huntingtin strictly depend on the presence of the endogenous self-perpetuating aggregated proteins (prions), which contain glutamine/asparagine-rich domains. Some chaperones of the Hsp100/70/40 complex, modulating propagation of yeast prions, were also reported to influence polyglutamine aggregation in yeast, but...
متن کاملA putative role of the Sup35p C-terminal domain in the cytoskeleton organization during yeast mitosis.
Sup35 protein (Sup35p), or eukaryotic peptide chain release factor GTP binding subunit (eRF3), is a well-known yeast prion responsible for the characteristic [PSI(+)] trait. N- and M-domains of this protein have been the foci of intensive research due to their importance for the prion formation. Sup35p C-terminal domain (Sup35pC) is essential for translation termination and cell viability. Dele...
متن کاملYeast Short-Lived Actin-Associated Protein Forms a Metastable Prion in Response to Thermal Stress.
Self-perpetuating ordered protein aggregates (amyloids and prions) are associated with a variety of neurodegenerative disorders. Although environmental agents have been linked to certain amyloid diseases, the molecular basis of their action remains unclear. We have employed endogenous yeast prions as a model system to study environmental control of amyloid formation. A short-lived actin-associa...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Molecular and cellular biology
دوره 26 2 شماره
صفحات -
تاریخ انتشار 2006