A formin Bni1p nucleates actin to assemble actin cables, which guide the polarized transport of secretory vesicles in budding yeast. We identified mutations that suppressed both the lethality and the ...excessive actin cable formation caused by overexpression of a truncated Bni1p (BNI1DeltaN). Two recessive mutations, act1-301 in the actin gene and sla2-82 in a gene involved in cortical actin patch assembly, were identified. The isolation of sla2-82 was unexpected, because cortical actin patches are required for the internalization step of endocytosis. Both act1-301 and sla2-82 exhibited synthetic growth defects with bni1Delta. act1-301, which resulted in an E117K substitution, interacted genetically with mutations in profilin (PFY1) and BUD6, suggesting that Act1-301p was not fully functional in formin-mediated polymerization. sla2-82 also interacted genetically with genes involved in actin cable assembly. Some experiments, however, suggested that the effects of sla2-82 were caused by depletion of actin monomers, because the temperature-sensitive growth phenotype of the bni1Delta sla2-82 mutant was suppressed by increased expression of ACT1. The isolation of suppressors of the BNI1DeltaN phenotype may provide a useful system for identification of actin amino-acid residues that are important for formin-mediated actin polymerization and mutations that affect the availability of actin monomers.
AF-6 contains two putative Ras-associating domains (RA domains) which are seen in several Ras effectors such as RalGDS and RIN1. We previously showed that an AF-6 fragment containing the ...amino-terminal (N-terminal) RA domain directly binds to activated Ras and ZO-1 in vitro. In this study, we showed that a single amino acid mutation in the N-terminal RA domain of AF-6 abolished the interaction of AF-6 with activated Ras and that the sites of this critical amino acid residue were similar to those for Raf-1 and RalGDS. The overexpression of the N-terminal RA domain of AF-6 inhibited the Ras-dependent c-fos promoter/enhancer stimulation in NIH3T3 cells. Endogenous AF-6 was coimmunoprecipitated with activated Ras from Rat1 cells expressing activated Ras. Moreover, we showed that AF-6 was coimmunoprecipitated with ZO-1 from Rat1 cells. Taken together, these results indicate that the Ras-interacting region on AF-6 is structurally similar to that on Raf-1 and on RalGDS and that AF-6 interacts with activated Ras and ZO-1 in vivo.
Jonas, the twelve-year old boy in Lois Lowry's The Giver, realizes the importance of retaining and sharing memories among his people, however hard and cruel they are. In preserving memories from ...generation to generation, one of the most familiar mnemonic devices is literature. In this sense, the role of literature education is very important. The act of teaching literature must be that of inheriting, imparting, and sharing memories through literary works.
In this essay, I will consider the role of literature in the process of learning in order to find out what Japanese language education can do. To grasp the learning process, it is primarily necessary ...to make clear the mechanism of reading, that is, the process of what a text invites the student-reader to read and how he or she responds to it. In so doing, I will depend for my method mainly on Louise Rosenblatt's work while partially applying those of Yoichi Komori, Manabu Sato, Kensuke Kono, Minoru Tanaka as well as David Bleich's and other meta-cognitive constructionism.
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