RESUMO
The molecular organization of cytokinesis proteins governs contractile ring function. We used single molecule localization microscopy in live cells to elucidate the molecular organization of cytokinesis proteins and relate it to the constriction rate of the contractile ring. Wild-type fission yeast cells assemble contractile rings by the coalescence of cortical proteins complexes called nodes whereas cells without Anillin/Mid1p (Δmid1) lack visible nodes yet assemble contractile rings competent for constriction from the looping of strands. We leveraged the Δmid1 contractile ring assembly mechanism to determine how two distinct molecular organizations, nodes versus strands, can yield functional contractile rings. Contrary to previous interpretations, nodes assemble in Δmid1 cells. Our results suggest that Myo2p heads condense upon interaction with actin filaments and an excess number of Myo2p heads bound to actin filaments hinders constriction thus reducing the constriction rate. Our work establishes a predictive correlation between the molecular organization of nodes and the behavior of the contractile ring.
Assuntos
Citocinese , Schizosaccharomyces/citologia , Acetiltransferases/metabolismo , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Modelos Biológicos , Mutação/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Fatores de TempoRESUMO
ABSTRACTHip fracture rehabilitation has two streams: high tolerance short duration (HTSD) and low tolerance long duration (LTLD). This study examined patient characteristics and outcomes in HTSD and LTLD associated with length of stay (LOS) and discharge destination. We retrospectively examined patients' medical charts following hip fracture surgery and collected demographic, functional, and health characteristics. A statistical analysis was done to describe the differences between HTSD (n = 73) and LTLD (n = 57) patient characteristics and their relationship with LOS and discharge destination. Those in LTLD were significantly older, less independent with prefracture bathing and instrumental activities of daily living, had lower Functional Independence Measure (FIM) admission scores, and more co-morbidities. Higher FIM motor score on admission in HTSD and greater change in FIM total score in LTLD was significantly correlated with discharge home. Diabetes in LTLD and lower total admission FIM in HTSD was significantly associated with increased LOS.
