A feed-forward pathway drives LRRK2 kinase membrane recruitment and activation

Activating mutations in the leucine-rich repeat kinase 2 (LRRK2) cause Parkinson’s disease, and previously we showed that activated LRRK2 phosphorylates a subset of Rab GTPases (Steger et al., 2017). Moreover, Golgi-associated Rab29 can recruit LRRK2 to the surface of the Golgi and activate it there for both auto- and Rab substrate phosphorylation. Here, we define the precise Rab29 binding region of the LRRK2 Armadillo domain between residues 360–450 and show that this domain, termed ‘site #1,’ can also bind additional LRRK2 substrates, Rab8A and Rab10. Moreover, we identify a distinct, N-terminal, higher-affinity interaction interface between LRRK2 phosphorylated Rab8 and Rab10 termed ‘site #2’ that can retain LRRK2 on membranes in cells to catalyze multiple, subsequent phosphorylation events. Kinase inhibitor washout experiments demonstrate that rapid recovery of kinase activity in cells depends on the ability of LRRK2 to associate with phosphorylated Rab proteins, and phosphorylated Rab8A stimulates LRRK2 phosphorylation of Rab10 in vitro. Reconstitution of purified LRRK2 recruitment onto planar lipid bilayers decorated with Rab10 protein demonstrates cooperative association of only active LRRK2 with phospho-Rab10-containing membrane surfaces. These experiments reveal a feed-forward pathway that provides spatial control and membrane activation of LRRK2 kinase activity

How do Service Providers and Clients Perceive Interorganizational Networks?

Interorganizational networks are important structures for both service providers, who must navigate them as part of their organizational roles, and clients, who use them for the purposes of receiving benefits. This research develops and tests a conceptual model that explains some of the differences in the ways that these two groups perceive these networks. Drawing on surveys/interviews with 200 clients and 63 service providers of agricultural development training in Burkina Faso, this research demonstrates that clients perceive interorganizational networks differently than service providers. In particular, these results demonstrate that service providers perceive more organizations in the network, more competitive and collaborative ties among those organizations, and more competitive ties per organization than clients. From these results, we draw implications for social network, development communication, and organizational fields’ research

Air Travel and Venous Thromboembolism: A Systematic Review

CONTEXT: Despite multiple attempts to document and quantify the danger of venous thromboembolism (VTE) following prolonged travel, there is still uncertainty about the magnitude of risk and what can be done to lower it. OBJECTIVES: To review the methodologic strength of the literature, estimate the risk of travel-related VTE, evaluate the efficacy of preventive treatments, and develop evidence-based recommendations for practice. DATA SOURCES: Studies identified from MEDLINE from 1966 through December 2005, supplemented by a review of the Cochrane Central Registry of Controlled Trials, the Database of Abstracts of Reviews of Effects, and relevant bibliographies. STUDY SELECTION: We included all clinical studies that either reported primary data concerning travel as a risk factor for VTE or tested preventive measures for travel-related VTE. DATA EXTRACTION AND ANALYSIS: Two reviewers reviewed each study independently to assess inclusion criteria, classify research design, and rate methodologic features. The effect of methodologic differences, VTE risk, and travel duration on VTE rate was evaluated using a logistic regression model. DATA SYNTHESIS: Twenty-four published reports, totaling 25 studies, met inclusion criteria (6 case-control studies, 10 cohort studies, and 9 randomized controlled trials). Method of screening for VTE [screening ultrasound compared to usual clinical care, odds ratio (OR) 390], outcome measure [all VTE compared to pulmonary embolism (PE) only, OR 21], duration of travel (<6 hours compared to 6–8 hours, OR 0.011), and clinical risk (“higher” risk travelers compared to “lower,” OR 3.6) were significantly related to VTE rate. Clinical VTE after prolonged travel is rare [27 PE per million flights diagnosed through usual clinical care, 0.05% symptomatic deep venous thrombosis (DVT) diagnosed through screening ultrasounds], but asymptomatic thrombi of uncertain clinical significance are more common. Graduated compression stockings prevented travel-related VTE (P < 0.05 in 4 of 6 studies), aspirin did not, and low-molecular-weight heparin (LMWH) showed a trend toward efficacy in one study. CONCLUSIONS: All travelers, regardless of VTE risk, should avoid dehydration and frequently exercise leg muscles. Travelers on a flight of less than 6 hours and those with no known risk factors for VTE, regardless of the duration of the flight, do not need DVT prophylaxis. Travelers with 1 or more risk factors for VTE should consider graduated compression stockings and/or LMWH for flights longer than 6 hours

Demographic and socioeconomic disparities in receipt of ophthalmology consultation for facial trauma

Objective Functional outcomes following facial and ocular trauma are time-sensitive and require prompt evaluation to minimise long-term vision loss, yet few studies have systematically evaluated disparities in the management of these cases. This study investigates whether a patient’s race/ethnicity, primary language, insurance status, gender or age affects receipt of ophthalmology consultation for facial trauma.Methods and analysis This study was a retrospective cohort analysis of patients from the Elmhurst City Hospital Trauma Registry in Queens, New York who were seen for facial trauma including open globe injuries and orbital fractures between January 2014 and May 2016.Results Of the 264 patients included, 43% reported as Hispanic, 23% white, 11% Asian, 8% black and 15% other/unknown. After controlling for confounding variables by multivariable logistic regression, neither race/ethnicity, gender, nor primary language were significantly associated with the likelihood of receiving an ophthalmology consult. However, patients with private insurance had 2.57 times greater odds of receiving an ophthalmology consultation than those with Medicaid or state corrections insurance (95% CI 1.37 to 4.95). As age increased, the likelihood of receiving an ophthalmology consultation decreased (p=0.009); patients 60 years of age and older had one-third the odds of ophthalmology consultation as younger patients (OR 0.33; 95% CI 0.16 to 0.68).Conclusions This study highlights that lack of ophthalmology consultation in patients with facial trauma is linked to age and underinsurance. Extra attention must be paid during primary assessments to ensure elderly patients and those with public insurance have equitable access to timely and appropriate care for facial trauma

An interaction network in the polymerase active site is a prerequisite for Watson-Crick base pairing in pol g

Pol gamma is essential for mitochondrial genome integrity. Mutations to the polymerase causes disruption to it's various functions. Mutations in the 853 site causes various neurological issues. Structural and computational analysis of the wild-type and the mutants show that the mutation inhibits the process of opening and closing of the polymerase necessary for nucleotide incorporation. Furthermore, the dNTP does not form Watson-Crick base pairing with the templating residue, which is necessary for the reaction to take place