The correspondence between James Hutton (1726–1797) and James Watt (1736–1819) with two letters from Hutton to George Clerk-Maxwell (1715–1784): Part I

In the collection of Watt's papers at Doldowlod, home of Lord Gibson-Watt, there are seven previously unpublished letters from James Hutton to James Watt, and four letters from Watt to Hutton, also unpublished. The letters were written between 1774 and 1795. Very little of Hutton's other correspondence survives, so these letters add significantly to our knowledge. The earliest letters, together with two letters to George Clerk-Maxwell (in the Scottish Record Office), describe geological tours that Hutton made through Wales, the Midlands, and the south-west of England in 1774. The correspondence after 1774, which will appear in a later edition of Annals of Science, reveals Watt's expertise in geology, and also discusses meteorology, varnish making, Symington's steam engines, the first experiments with steam navigation, pneumatic medicine, and other topics.     

Sir William Hamilton (1730–1803): His work and influence in geology

In the formative period of London's scientific instrument industry membership of a guild was a necessary step towards owning a business in the City. Through the guilds' formal system of apprenticeship, boys received first-class training in a skilled trade, and learned essential marketing and managerial techniques. By analysing the guilds' records of apprenticeship and subsequent guild life it is possible to determine chains of masters and apprentices by which the knowledge passed from generation to generation. At the same time, dates can be established for the training and subsequent working life of many known makers. The chains of knowledge reveal new and often important masters who were previously unknown because, by chance, their instruments or advertisements have not survived to the present day. Two guilds have been used to illustrate the chains: Broderers' Company and Joiners' Company.     

Ablation of cyclase-associated protein 2 (CAP2) leads to cardiomyopathy

Cyclase-associated proteins are highly conserved proteins that have a role in the regulation of actin dynamics. Higher eukaryotes have two isoforms, CAP1 and CAP2. To study the in vivo function of CAP2, we generated mice in which the CAP2 gene was inactivated by a gene-trap approach. Mutant mice showed a decrease in body weight and had a decreased survival rate. Further, they developed a severe cardiac defect marked by dilated cardiomyopathy (DCM) associated with drastic reduction in basal heart rate and prolongations in atrial and ventricular conduction times. Moreover, CAP2-deficient myofibrils exhibited reduced cooperativity of calcium-regulated force development. At the microscopic level, we observed disarrayed sarcomeres with development of fibrosis. We analyzed CAP2’s role in actin assembly and found that it sequesters G-actin and efficiently fragments filaments. This activity resides completely in its WASP homology domain. Thus CAP2 is an essential component of the myocardial sarcomere and is essential for physiological functioning of the cardiac system, and a deficiency leads to DCM and various cardiac defects.     

Structural basis of bacterial defense against g-type lysozyme-based innate immunity

Gram-negative bacteria can produce specific proteinaceous inhibitors to defend themselves against the lytic action of host lysozymes. So far, four different lysozyme inhibitor families have been identified. Here, we report the crystal structure of the Escherichia coli periplasmic lysozyme inhibitor of g-type lysozyme (PliG-Ec) in complex with Atlantic salmon g-type lysozyme (SalG) at a resolution of 0.95 Å, which is exceptionally high for a complex of two proteins. The structure reveals for the first time the mechanism of g-type lysozyme inhibition by the PliG family. The latter contains two specific conserved regions that are essential for its inhibitory activity. The inhibitory complex formation is based on a double ‘key-lock’ mechanism. The first key-lock element is formed by the insertion of two conserved PliG regions into the active site of the lysozyme. The second element is defined by a distinct pocket of PliG accommodating a lysozyme loop. Computational analysis indicates that this pocket represents a suitable site for small molecule binding, which opens an avenue for the development of novel antibacterial agents that suppress the inhibitory activity of PliG.     

The role of estrogen receptor α in the regulation of bone and growth plate cartilage

Estrogens are important endocrine regulators of skeletal growth and maintenance in both females and males. Studies have demonstrated that the estrogen receptor (ER)-α is the main mediator of these estrogenic effects in bone. Therefore, estrogen signaling via ERα is a target both for affecting longitudinal bone growth and bone remodeling. However, treatment with estradiol (E2) leads to an increased risk of side effects such as venous thromboembolism and breast cancer. Thus, an improved understanding of the signaling pathways of ERα will be essential in order to find better bone specific treatments with minimal adverse effects for different estrogen-related bone disorders. This review summarizes the recent data regarding the intracellular signaling mechanisms, in vivo, mediated by the ERα activation functions (AFs), AF-1 and AF-2, and the effect on bone, growth plate and other estrogen responsive tissues. In addition, we review the recent cell-specific ERα-deleted mouse models lacking ERα specifically in neuronal cells or growth plate cartilage. The newly characterized signaling pathways of estrogen, described in this review, provide a better understanding of the ERα signaling pathways, which may facilitate the design of new, bone-specific treatment strategies with minimal adverse effects.