RESUMO
During ascospore formation in Saccharomyces cerevisiae, the secretory pathway is reorganized to create new intracellular compartments, termed prospore membranes. Prospore membranes engulf the nuclei produced by the meiotic divisions, giving rise to individual spores. The shape and growth of prospore membranes are constrained by cytoskeletal structures, such as septin proteins, that associate with the membranes. Green fluorescent protein (GFP) fusions to various proteins that associate with septins at the bud neck during vegetative growth as well as to proteins encoded by genes that are transcriptionally induced during sporulation were examined for their cellular localization during prospore membrane growth. We report localizations for over 100 different GFP fusions, including over 30 proteins localized to the prospore membrane compartment. In particular, the screen identified IRC10 as a new component of the leading-edge protein complex (LEP), a ring structure localized to the lip of the prospore membrane. Localization of Irc10 to the leading edge is dependent on SSP1, but not ADY3. Loss of IRC10 caused no obvious phenotype, but an ady3 irc10 mutant was completely defective in sporulation and displayed prospore membrane morphologies similar to those of an ssp1 strain. These results reveal the architecture of the LEP and provide insight into the evolution of this membrane-organizing complex.
Assuntos
Membrana Celular/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Esporos Fúngicos/metabolismo , Sequência de Aminoácidos , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Membrana/genética , Dados de Sequência Molecular , Fenótipo , Ligação Proteica , Transporte Proteico , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia , Proteínas de Saccharomyces cerevisiae/genética , Esporos Fúngicos/citologiaRESUMO
INTRODUCTION: Endodontic-periodontal combined lesions pose a treatment challenge for clinicians, especially when the lesion is persistent and does not show signs of healing after initial endodontic treatment. This case report describes interdisciplinary management of a non-healing combined endodontic-periodontal lesion related to a peri-apical cyst, through a combined approach of apicoectomy and guided tissue regeneration (GTR) with enamel matrix derivative (EMD). Most documented cases have been treated in a sequential manner, with minimal literature present on the effects of a combined approach utilizing EMD for the treatment of these lesions. CASE PRESENTATION: A 72-year-old male patient presented with an endodontic-periodontal lesion at tooth #31 initially treated with nonsurgical root canal therapy. The lesion was not responsive to initial endodontic treatment. The patient was informed of questionable prognosis, however wished to save the tooth. Tooth #31 was treated via a combination approach of apicoectomy with bioceramic putty retrograde filling, followed by GTR of the defect using allograft, EMD, and resorbable barrier membrane. The lesion was biopsied and diagnosed as a periapical cyst. Clinical and radiographic examination at 1 year showed resolution of lesion, reduction in probing depths, and good bone fill of the defect. CONCLUSION: Traditionally, endodontic-periodontal lesions, which were not responsive to initial therapy, would be given a questionable prognosis and be extracted. This case demonstrates that non-healing, peri-apical lesions may be cystic in nature and effectively managed utilizing a combined approach, with apicoectomy and GTR with EMD, to produce a stable outcome.