Competition between myosin II and β-spectrin regulates cytoskeletal tension.

Spectrins are membrane cytoskeletal proteins generally thought to function as heterotetramers comprising two α-spectrins and two β-spectrins. They influence cell shape and Hippo signaling, but the mechanism by which they influence Hippo signaling has remained unclear. We have investigated the role and regulation of the β-heavy spectrin (β-spectrin, encoded by the gene) in wing imaginal discs.

Analysis of the Drosophila Ajuba LIM protein defines functions for distinct LIM domains.

The Ajuba LIM protein Jub mediates regulation of Hippo signaling by cytoskeletal tension through interaction with the kinase Warts and participates in feedback regulation of junctional tension through regulation of the cytohesin Steppke. To investigate how Jub interacts with and regulates its distinct partners, we investigated the ability of Jub proteins missing different combinations of its three LIM domains to rescue jub phenotypes and to interact with α-catenin, Warts and Steppke. Multiple regions of Jub contribute to its ability to bind α-catenin and to localize to adherens junctions in Drosophila wing imaginal discs.

Hair cortisol in polycystic ovary syndrome.

The aim of the study was to evaluate adrenal axis hyperactivation measuring hair cortisol levels, and its influence on the relationship among metabolic parameters, inflammation markers and androgens in adult women with PCOS. 44 women (18-34 years) with PCOS diagnosis and a control group of 49 healthy women (19-35 years) were included. In both gropus body mass index (BMI) was calculated and waist circumference (WC) was measured.

E and Gamma distributions in polygonal networks.

From solar supergranulation to salt flat in Bolivia, from veins on leaves to cells on Drosophila wing discs, polygon-based networks exhibit great complexities, yet similarities and consistent patterns emerge. Based on analysis of 99 polygonal tessellations of a wide variety of physical origins, this work demonstrates the ubiquity of an exponential distribution in the squared norm of the deformation tensor, E, which directly leads to the ubiquitous presence of Gamma distributions in polygon aspect ratio as recently demonstrated by Atia [Nat. Phys.

Hair cortisol reduction and social integration enhancement after a mindfulness-based intervention in children.

Background: Over recent decades, chronic stress at an early age has become a worrying health problem in children. We seek to evaluate an intervention involving mindfulness-based practices and prosocial activities in 7- to 8-year-old children.

Methods: Stress levels were determined using hair cortisol concentration (HCC), and social integration was measured by means of a sociogram.

Evaluation of stress, burnout and hair cortisol levels in health workers at a University Hospital during COVID-19 pandemic.

Unlabelled: In the critical context of COVID-19 pandemic, healthcare workers are on the front line, participating directly in the care, diagnosis, and treatment of patients with COVID-19. This exposes them to a higher risk of developing chronic stress, psychological distress, and any other mental health symptoms.

Objective: to evaluate stress and burnout in a health workers population and, in addition, to measure hair cortisol concentration as a current biomarker of stress.

TRIP6 is required for tension at adherens junctions.

Hippo signaling mediates influences of cytoskeletal tension on organ growth. TRIP6 and LIMD1 have each been identified as being required for tension-dependent inhibition of the Hippo pathway LATS kinases and their recruitment to adherens junctions, but the relationship between TRIP6 and LIMD1 was unknown. Using siRNA-mediated gene knockdown, we show that TRIP6 is required for LIMD1 localization to adherens junctions, whereas LIMD1 is not required for TRIP6 localization.

Integration of Hippo-YAP Signaling with Metabolism.

The Hippo-Yes-associated protein (YAP) signaling network plays a central role as an integrator of signals that control cellular proliferation and differentiation. The past several years have provided an increasing appreciation and understanding of the diverse mechanisms through which metabolites and metabolic signals influence Hippo-YAP signaling, and how Hippo-YAP signaling, in turn, controls genes that direct cellular and organismal metabolism. These connections enable Hippo-YAP signaling to coordinate organ growth and homeostasis with nutrition and metabolism.

Rapping about Mechanotransduction.

Mechanical cues can regulate cell proliferation and differentiation through the Hippo-YAP signaling network. Reporting in Nature, Meng et al. (2018) show that the Ras-related GTPase RAP2 connects extracellular matrix stiffness to Hippo pathway regulation, adding to our understanding of how mechanical cues are converted into changes in YAP activity.

Tension-dependent regulation of mammalian Hippo signaling through LIMD1.

Hippo signaling is regulated by biochemical and biomechanical cues that influence the cytoskeleton, but the mechanisms that mediate this have remained unclear. We show that all three mammalian Ajuba family proteins - AJUBA, LIMD1 and WTIP - exhibit tension-dependent localization to adherens junctions, and that both LATS family proteins, LATS1 and LATS2, exhibit an overlapping tension-dependent junctional localization. This localization of Ajuba and LATS family proteins is also influenced by cell density, and by Rho activation.

BAX inhibitor-1 regulates autophagy by controlling the IRE1α branch of the unfolded protein response.

[Image: see text]

Drosophila p115 is required for Cdk1 activation and G2/M cell cycle transition.

Golgi complex inheritance and its relationship with the cell cycle are central in cell biology. Golgi matrix proteins, known as golgins, are one of the components that underlie the shape and functionality of this organelle. In mammalian cells, golgins are phosphorylated during mitosis to allow fragmentation of the Golgi ribbon and they also participate in spindle dynamics; both processes are required for cell cycle progression.

Differential growth triggers mechanical feedback that elevates Hippo signaling.

Mechanical stress can influence cell proliferation in vitro, but whether it makes a significant contribution to growth control in vivo, and how it is modulated and experienced by cells within developing tissues, has remained unclear. Here we report that differential growth reduces cytoskeletal tension along cell junctions within faster-growing cells. We propose a theoretical model to explain the observed reduction of tension within faster-growing clones, supporting it by computer simulations based on a generalized vertex model.

The Drosophila EKC/KEOPS complex: roles in protein synthesis homeostasis and animal growth.

The TOR signaling pathway is crucial in the translation of nutritional inputs into the protein synthesis machinery regulation, allowing animal growth. We recently identified the Bud32 (yeast)/PRPK (human) ortholog in Drosophila, Prpk (p53-related protein kinase), and found that it is required for TOR kinase activity. Bud32/PRPK is an ancient and atypical kinase conserved in evolution from Archeae to humans, being essential for Archeae.

Drosophila p53-related protein kinase is required for PI3K/TOR pathway-dependent growth.

Cell growth and proliferation are pivotal for final organ and body size definition. p53-related protein kinase (Bud32/PRPK) has been identified as a protein involved in proliferation through its effects on transcription in yeast and p53 stabilization in human cell culture. However, the physiological function of Bud32/PRPK in metazoans is not well understood.

BAX inhibitor-1 regulates autophagy by controlling the IRE1α branch of the unfolded protein response.

Both autophagy and apoptosis are tightly regulated processes playing a central role in tissue homeostasis. Bax inhibitor 1 (BI-1) is a highly conserved protein with a dual role in apoptosis and endoplasmic reticulum (ER) stress signalling through the regulation of the ER stress sensor inositol requiring kinase 1 α (IRE1α). Here, we describe a novel function of BI-1 in the modulation of autophagy.

The import of S-adenosylmethionine into the Golgi apparatus is required for the methylation of homogalacturonan.

S-adenosylmethionine (SAM) is the substrate used in the methylation of homogalacturonan (HGA) in the Golgi apparatus. SAM is synthesized in the cytosol, but it is not currently known how it is then transported into the Golgi. In this study, we find that HGA methyltransferase is present in Golgi-enriched fractions and that its catalytic domain faces the lumen of this organelle.