Exploiting the MDM2-CK1 alpha Protein-Protein Interface to Develop Novel Biologics That Induce UBL-Kinase-Modification and Inhibit Cell Growth

Protein-protein interactions forming dominant signalling events are providing ever-growing platforms for the development of novel Biologic tools for controlling cell growth. Casein Kinase 1 α (CK1α) forms a genetic and physical interaction with the murine double minute chromosome 2 (MDM2) oncoprotein resulting in degradation of the p53 tumour suppressor. Pharmacological inhibition of CK1 increases p53 protein level and induces cell death, whilst small interfering RNA-mediated depletion of CK1α stabilizes p53 and induces growth arrest. We mapped the dominant protein-protein interface that stabilizes the MDM2 and CK1α complex in order to determine whether a peptide derived from the core CK1α-MDM2 interface form novel Biologics that can be used to probe the contribution of the CK1-MDM2 protein-protein interaction to p53 activation and cell viability. Overlapping peptides derived from CK1α were screened for dominant MDM2 binding sites using (i) ELISA with recombinant MDM2; (ii) cell lysate pull-down towards endogenous MDM2; (iii) MDM2-CK1α complex-based competition ELISA; and (iv) MDM2-mediated ubiquitination. One dominant peptide, peptide 35 was bioactive in all four assays and its transfection induced cell death/growth arrest in a p53-independent manner. Ectopic expression of flag-tagged peptide 35 induced a novel ubiquitin and NEDD8 modification of CK1α, providing one of the first examples whereby NEDDylation of a protein kinase can be induced. These data identify an MDM2 binding motif in CK1α which when isolated as a small peptide can (i) function as a dominant negative inhibitor of the CK1α-MDM2 interface, (ii) be used as a tool to study NEDDylation of CK1α, and (iii) reduce cell growth. Further, this approach provides a technological blueprint, complementing siRNA and chemical biology approaches, by exploiting protein-protein interactions in order to develop Biologics to manipulate novel types of signalling pathways such as cross-talk between NEDDylation, protein kinase signalling, and cell survival

Quasar UV/X-ray relation luminosity distances are shorter than reverberation-measured radius-luminosity relation luminosity distances

We use measurements of 59/58 quasars (QSOs), over a redshift range $0.0041\leq z \leq 1.686$, to do a comparative study of the radius--luminosity ($R-L$) and X-ray$-$UV luminosity ($L_X-L_{UV}$) relations and the implication of these relations for cosmological parameter estimation. By simultaneously determining $R-L$ or $L_X-L_{UV}$ relation parameters and cosmological parameters in six different cosmological models, we find that both $R-L$ and $L_X-L_{UV}$ relations are standardizable but provide only weak cosmological parameter constraints, with $L_X-L_{UV}$ relation data favoring larger current non-relativistic matter density parameter $\Omega_{m0}$ values than $R-L$ relation data and most other available data. We derive $L_X-L_{UV}$ and $R-L$ luminosity distances for each of the sources in the six cosmological models and find that $L_X-L_{UV}$ relation luminosity distances are shorter than $R-L$ relation luminosity distances as well as standard flat $\Lambda$CDM model luminosity distances. This explains why $L_X-L_{UV}$ relation QSO data favor larger $\Omega_{m0}$ values than do $R-L$ relation QSO data or most other cosmological measurements. While our sample size is small and only spans a small $z$ range, these results indicate that more work is needed to determine whether the $L_X-L_{UV}$ relation can be used as a cosmological probe.Comment: 20 pages, 10 figures, MNRAS in pres

A theory of change roadmap for universal health coverage in India

The Theory of Change (ToC) approach is one of the methodologies that the Lancet Citizens' Commission has chosen to build a roadmap to achieving Universal Healthcare (UHC) in India in the next 10 years. The work of the Citizens' Commission is organized around five workstreams: Finance, Human Resources for Health (HRH), Citizens' Engagement, Governance, and Technology. Five ToC workshops were conducted, one for each workstream. Individual workshop outputs were then brought together in two cross-workstream workshops where a sectoral Theory of Change for UHC was derived. Seventy-four participants, drawn from the Commission or invited for their expertise, and representing diverse stakeholders and sectors concerned with UHC, contributed to these workshops. A reimagined healthcare system achieves (1) enhanced transparency, accountability, and responsiveness; (2) improved quality of health services; (3) accessible, comprehensive, connected, and affordable care for all; (4) equitable, people-centered and safe health services; and (5) trust in the health system. For a mixed system like India's, achieving these high ideals will require all actors, public, private and civil society, to collaborate and bring about this transformation. During the consultation, paradigm shifts emerged, which were structural or systemic assumptions that were deemed necessary for the realization of all interventions. Critical points of consensus also emerged from the workshops, such as the need for citizen-centricity, greater efficiency in the use of public finances for health care, shifting to team-based managed care, empowerment of frontline health workers, the appropriate use of technology across all phases of patient care, and moving toward an articulation of positive health and wellbeing. Critical areas of contention that remained related to the role of the private sector, especially around financing and service delivery. Few issues for further consultation and research were noted, such as payment for performance across both public and private sectors, the use of accountability metrics across both public and private sectors, and the strategies for addressing structural barriers to realizing the proposed paradigm shifts. As the ToCs were developed in expert groups, citizens' consultations and consultations with administrative leaders were recommended to refine and ground the ToC, and therefore the roadmap to realize UHC, in people's lived reality