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Biomedical subjects

Thomas F Lerch

Publications and source records attributed to Thomas F Lerch.

3 recordsLinked to original sources

The structures that underlie normal reproductive function.

The mechanisms and physiology of reproductive function have fascinated scientists throughout time. Recent cellular and molecular level structural studies have provided unprecedented insights into reproductive systems and signaling networks. This 'cutting edge' editorial provides a recent example in each of these areas, namely, the anatomical integrity of the follicle, the molecular structure of activin with its binding partners and the molecular regulation of inhibin. These three examples of structure informing function help explain reproductive health and may provide solutions to reproductive disease.

Endocrine System↗

The structural basis of TGF-beta, bone morphogenetic protein, and activin ligand binding.

The transforming growth factor-beta (TGF-beta) superfamily is a large group of structurally related growth factors that play prominent roles in a variety of cellular processes. The importance and prevalence of TGF-beta signaling are also reflected by the complex network of check points that exist along the signaling pathway, including a number of extracellular antagonists and membrane-level signaling modulators. Recently, a number of important TGF-beta crystal structures have emerged and given us an unprecedented clarity on several aspects of the signal transduction process. This review will highlight these latest advances and present our current understanding on the mechanisms of specificity and regulation on TGF-beta signaling outside the cell.

Activins↗

The structure of the follistatin:activin complex reveals antagonism of both type I and type II receptor binding.

TGF-beta ligands stimulate diverse cellular differentiation and growth responses by signaling through type I and II receptors. Ligand antagonists, such as follistatin, block signaling and are essential regulators of physiological responses. Here we report the structure of activin A, a TGF-beta ligand, bound to the high-affinity antagonist follistatin. Two follistatin molecules encircle activin, neutralizing the ligand by burying one-third of its residues and its receptor binding sites. Previous studies have suggested that type I receptor binding would not be blocked by follistatin, but the crystal structure reveals that the follistatin N-terminal domain has an unexpected fold that mimics a universal type I receptor motif and occupies this receptor binding site. The formation of follistatin:BMP:type I receptor complexes can be explained by the stoichiometric and geometric arrangement of the activin:follistatin complex. The mode of ligand binding by follistatin has important implications for its ability to neutralize homo- and heterodimeric ligands of this growth factor family.

Activin Receptors, Type I↗