RESUMO
KEY MESSAGES: SUP gene family expression and regulation patterns reported in dioecious woody plant. Phylogenetic and nucleotide diversity analysis indicated PtoSUP1 is highly conserved and has undergone strong purifying selection. The molecular basis of SUPERMAN (SUP) regulation during floral development in monoecious plants has been extensively studied, but little is known of the SUP gene family in dioecious woody plants. In this study, we systematically examined the diversification of the SUP gene family in Populus, integrating genomic organization, expression, and phylogeny data. SUP family members showed sex-specific expression throughout flower development. Transcript profiling of rare gynomonoecious poplar flowers revealed that a significant reduction in PtoSUP1 mRNA might be important for stamen development in gynomonoecious poplar flowers. We found that the coding regions of Populus SUP genes are very highly conserved and that synonymous sites in exon regions have undergone strong purifying selection during SUP evolution in Populus. These results indicate that SUP genes play an important role in floral development of dioecious plants. Expression analysis of SUP suggested possible regulatory mechanisms for gynomonoecious poplar flower development. These findings provide an important insight into the mechanisms of the evolution of SUP function and may help enable engineered regulation of flower development for breeding improved tree varieties.
Assuntos
Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Variação Genética , Família Multigênica , Nucleotídeos/genética , Proteínas de Plantas/genética , Populus/genética , Clima , Códon/genética , Flores/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Dados de Sequência Molecular , Mutação/genética , Filogenia , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Populus/crescimento & desenvolvimento , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Especificidade da EspécieRESUMO
Pannexin1 (PANX1) is a large-pore ATP efflux channel with a broad distribution, which allows the exchange of molecules and ions smaller than 1 kDa between the cytoplasm and extracellular space. In this study, we show that in human macrophages PANX1 expression is upregulated by diverse stimuli that promote pyroptosis, which is reminiscent of the previously reported lipopolysaccharide-induced upregulation of PANX1 during inflammasome activation. To further elucidate the function of PANX1, we propose the full-length human Pannexin1 (hPANX1) model through cryo-electron microscopy (cryo-EM) and molecular dynamics (MD) simulation studies, establishing hPANX1 as a homo-heptamer and revealing that both the N-termini and C-termini protrude deeply into the channel pore funnel. MD simulations also elucidate key energetic features governing the channel that lay a foundation to understand the channel gating mechanism. Structural analyses, functional characterizations, and computational studies support the current hPANX1-MD model, suggesting the potential role of hPANX1 in pyroptosis during immune responses.