RESUMO
In metazoans, most proteins have pleiotropic cellular functions and have the ability to interact with several factors to accomplish these different functions. This is the case of eukaryotic ERH proteins, a family of homodimeric proteins involved in DNA replication and cell cycle control as well as in gene silencing by contributing either to the biogenesis of small interference RNAs (miRNAs, piRNAs) or to the recruitment of RNA decay machineries. Very recently, several crystal structures describing complexes formed by eukaryotic ERH proteins and several small peptides from various partners have highlighted the existence of different binding sites on the surface of ERH proteins. In this issue of The FEBS Journal, Wang et al. present the crystal structure of the complex formed between the human ERH protein and a short peptide of the CIZ1 protein, one of its partners. Altogether, this information will be particularly important for future studies aimed at dissecting the different biological functions governed by this family of highly conserved proteins. Comment on: https://doi.org/10.1111/febs.16611.
Assuntos
Proteínas de Ciclo Celular , Inativação Gênica , Fatores de Transcrição , Humanos , Divisão Celular , Replicação do DNA , MicroRNAs , Proteínas Nucleares/genética , RNA Interferente Pequeno/genética , Fatores de Transcrição/metabolismo , Proteínas de Ciclo Celular/metabolismoRESUMO
Piwi-interacting RNAs (piRNAs) constitute a class of small RNAs that bind PIWI proteins and are essential to repress transposable elements in the animal germline, thereby promoting genome stability and maintaining fertility. C. elegans piRNAs (21U RNAs) are transcribed individually from minigenes as precursors that require 5' and 3' processing. This process depends on the PETISCO complex, consisting of four proteins: IFE-3, TOFU-6, PID-3, and ERH-2. We used biochemical and structural biology approaches to characterize the PETISCO architecture and its interaction with RNA, together with its effector proteins TOST-1 and PID-1. These two proteins define different PETISCO functions: PID-1 governs 21U processing, whereas TOST-1 links PETISCO to an unknown process essential for early embryogenesis. Here, we show that PETISCO forms an octameric assembly with each subunit present in two copies. Determination of structures of the TOFU-6/PID-3 and PID-3/ERH-2 subcomplexes, supported by in vivo studies of subunit interaction mutants, allows us to propose a model for the formation of the TOFU-6/PID-3/ERH-2 core complex and its functionality in germ cells and early embryos. Using NMR spectroscopy, we demonstrate that TOST-1 and PID-1 bind to a common surface on ERH-2, located opposite its PID-3 binding site, explaining how PETISCO can mediate different cellular roles.
Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Elementos de DNA Transponíveis , Células Germinativas/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismoRESUMO
A indústria de alimentos pet está em constante expansão e vêm seguindo as tendências da alimentação humana, com o objetivo de promover benefícios para a saúde dos animais e satisfação aos tutores. A introdução de compostos naturais na formulação de rações permite a redução da ingestão de aditivos químicos, transgênicos e a possibilidade de ofertar ao animal uma dieta equilibrada e funcional. Desta forma, o presente estudo teve como intuito realizar análises: bromatológica, físico-química e a influência da adição da farinha de uva na validade comercial de um biscoito canino natural. Os resultados foram considerados satisfatórios conforme a legislação vigente. Em virtude disso, a adição da farinha de uva promoveu retardo da oxidação lipídica, contribuindo para o aumento de nove dias da validade comercial.