Suchergebnisse

This study examines the perceptions of directors in Australian public listed companies about their access to information for their role as directors. We focus on information costs and information asymmetry. Directors' perceptions of the relationship between the composition of Boards, the perceived roles of Boards and the information requirements to fulfil those roles were explored in interviews with 45 directors from public listed companies. Implicit in Agency Theory is the assumption that independent directors have free access to the information required to fulfil their role in monitoring and control. We found, however, demonstrable evidence of information asymmetry. The central finding was that directors perceive that the CEO and Executive have the controlling power over information. The provision of appropriate information for Board decisions is perceived to hinge on the "integrity" of the CEO and Executive. This emphasis on integrity and "good companies" does appear consistent with the Stewardship Theory of governance. It raises as a question for future research the possible alternative relationships between Boards and management. The directors interviewed discussed a range of strategies they used to keep themselves informed and made observations of additions to information that they believed should be available as a matter of course.

All animal cells use the motor cytoplasmic dynein 1 (dynein) to transport diverse cargo toward microtubule minus ends and to organize and position microtubule arrays such as the mitotic spindle. Cargo-specific adaptors engage with dynein to recruit and activate the motor, but the molecular mechanisms remain incompletely understood. Here, we use structural and dynamic nuclear magnetic resonance (NMR) analysis to demonstrate that the C-terminal region of human dynein light intermediate chain 1 (LIC1) is intrinsically disordered and contains two short conserved segments with helical propensity. NMR titration experiments reveal that the first helical segment (helix 1) constitutes the main interaction site for the adaptors Spindly (SPDL1), bicaudal D homolog 2 (BICD2), and Hook homolog 3 (HOOK3). In vitro binding assays show that helix 1, but not helix 2, is essential in both LIC1 and LIC2 for binding to SPDL1, BICD2, HOOK3, RAB-interacting lysosomal protein (RILP), RAB11 family-interacting protein 3 (RAB11FIP3), ninein (NIN), and trafficking kinesin-bind-ing protein 1 (TRAK1). Helix 1 is sufficient to bind RILP, whereas other adaptors require additional segments preceding helix 1 for efficient binding. Point mutations in the C-terminal helix 1 of Caenorhabditis elegans LIC, introduced by genome editing, severely affect development, locomotion, and life span of the animal and disrupt the distribution and transport kinetics of membrane cargo in axons of mechanosensory neurons, identical to what is observed when the entire LIC C-terminal region is deleted. Deletion of the C-terminal helix 2 delays dynein-dependent spindle positioning in the one-cell embryo but overall does not significantly perturb dynein function. We conclude that helix 1 in the intrinsically disordered region of LIC provides a conserved link between dynein and structurally diverse cargo adaptor families that is critical for dynein function in vivo. ; This work was financed by the Fundo Europeu de Desenvolvimento Regional (FEDER) through the Norte Portugal Regional Operational Programme (NORTE 2020), Portugal 2020 (RG); by the Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project NORTE-01-0145-FEDER-030507 (RG); by FCT fellowships IF/01015/2013/CP1157/CT0006 (RG) and SFRH/ BPD/101898/2014 (DJB); by the European Research Council under the European Union's Seventh Framework Programme, ERC grant agreement no. ERC-2013-StG-338410-DYNEINOME (RG), and by a start-up package of the University of Colorado (BV). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.