Catálogo de publicaciones - revistas

<jats:p>Activating mutations in leucine-rich repeat kinase 2 (LRRK2) represent the most common cause of monogenic Parkinson's disease. LRRK2 is a large multidomain protein kinase that phosphorylates a specific subset of the ∼65 human Rab GTPases, which are master regulators of the secretory and endocytic pathways. After phosphorylation by LRRK2, Rabs lose the capacity to bind cognate effector proteins and guanine nucleotide exchange factors. Moreover, the phosphorylated Rabs cannot interact with their cognate prenyl-binding retrieval proteins (also known as guanine nucleotide dissociation inhibitors) and, thus, they become trapped on membrane surfaces. Instead, they gain the capacity to bind phospho-Rab-specific effector proteins, such as RILPL1, with resulting pathological consequences. Rab proteins also act upstream of LRRK2 by controlling its activation and recruitment onto membranes. LRRK2 signaling is counteracted by the phosphoprotein phosphatase PPM1H, which selectively dephosphorylates phospho-Rab proteins. We present here our current understanding of the structure, biochemical properties, and cell biology of LRRK2 and its related paralog LRRK1 and discuss how this information guides the generation of LRRK2 inhibitors for the potential benefit of patients.</jats:p>

<jats:p>Human lectins are integral to maintaining microbial homeostasis on the skin, in the blood, and at mucosal barriers. These proteins can recognize microbial glycans and inform the host about its microbial status. In accordance with their roles, their production can vary with tissue type. They also can have unique structural and biochemical properties, and they can influence microbial colonization at sites proximal and distal to their tissue of origin. In line with their classification as innate immune proteins, soluble lectins have long been studied in the context of acute infectious disease, but only recently have we begun to appreciate their roles in maintaining commensal microbial communities (i.e., the human microbiota). This review provides an overview of soluble lectins that operate at host–microbe interfaces, their glycan recognition properties, and their roles in physiological and pathological mechanisms.</jats:p>

<jats:p>Three decades of studies on the multifunctional 6-deoxyerythronolide B synthase have laid a foundation for understanding the chemistry and evolution of polyketide antibiotic biosynthesis by a large family of versatile enzymatic assembly lines. Recent progress in applying chemical and structural biology tools to this prototypical assembly-line polyketide synthase (PKS) and related systems has highlighted several features of their catalytic cycles and associated protein dynamics. There is compelling evidence that multiple mechanisms have evolved in this enzyme family to channel growing polyketide chains along uniquely defined sequences of 10–100 active sites, each of which is used only once in the overall catalytic cycle of an assembly-line PKS. Looking forward, one anticipates major advances in our understanding of the mechanisms by which the free energy of a repetitive Claisen-like reaction is harnessed to guide the growing polyketide chain along the assembly line in a manner that is kinetically robust yet evolutionarily adaptable.</jats:p>

<jats:p>The complex carbohydrate structures decorating human proteins and lipids, also called glycans, are abundantly present at cell surfaces and in the secretome. Glycosylation is vital for biological processes including cell–cell recognition, immune responses, and signaling pathways. Therefore, the structural and functional characterization of the human glycome is gaining more and more interest in basic biochemistry research and in the context of developing new therapies, diagnostic tools, and biotechnology applications. For glycomics to reach its full potential in these fields, it is critical to appreciate the specific factors defining the function of the human glycome. Here, we review the glycosyltransferases (the writers) that form the glycome and the glycan-binding proteins (the readers) with an essential role in decoding glycan functions. While abundantly present throughout different cells and tissues, the function of specific glycosylation features is highly dependent on their context. In this review, we highlight the relevance of studying the glycome in the context of specific carrier proteins, cell types, and subcellular locations. With this, we hope to contribute to a richer understanding of the glycome and a more systematic approach to identifying the roles of glycosylation in human physiology.</jats:p>

<jats:p>During the last ten years, developments in cryo–electron microscopy have transformed our understanding of eukaryotic ribosome assembly. As a result, the field has advanced from a list of the vast array of ribosome assembly factors toward an emerging molecular movie in which individual frames are represented by structures of stable ribosome assembly intermediates with complementary biochemical and genetic data. In this review, we discuss the mechanisms driving the assembly of yeast and human small and large ribosomal subunits. A particular emphasis is placed on the most recent findings that illustrate key concepts of ribosome assembly, such as folding of preribosomal RNA, the enforced chronology of assembly, enzyme-mediated irreversible transitions, and proofreading of preribosomal particles.</jats:p>

<jats:p> RAF family protein kinases are a key node in the RAS/RAF/MAP kinase pathway, the signaling cascade that controls cellular proliferation, differentiation, and survival in response to engagement of growth factor receptors on the cell surface. Over the past few years, structural and biochemical studies have provided new understanding of RAF autoregulation, RAF activation by RAS and the SHOC2 phosphatase complex, and RAF engagement with HSP90–CDC37 chaperone complexes. These studies have important implications for pharmacologic targeting of the pathway. They reveal RAF in distinct regulatory states and show that the functional RAF switch is an integrated complex of RAF with its substrate (MEK) and a 14-3-3 dimer. Here we review these advances, placing them in the context of decades of investigation of RAF regulation. We explore the insights they provide into aberrant activation of the pathway in cancer and RASopathies (developmental syndromes caused by germline mutations in components of the pathway). </jats:p><jats:p> Expected final online publication date for the Annual Review of Biochemistry , Volume 93 is June 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates. </jats:p>

<jats:p> The nicotinic acetylcholine receptor has served, since its biochemical identification in the 1970s, as a model of an allosteric ligand-gated ion channel mediating signal transition at the synapse. In recent years, the application of X-ray crystallography and high-resolution cryo–electron microscopy, together with molecular dynamic simulations of nicotinic receptors and homologs, have opened a new era in the understanding of channel gating by the neurotransmitter. They reveal, at atomic resolution, the diversity and flexibility of the multiple ligand-binding sites, including recently discovered allosteric modulatory sites distinct from the neurotransmitter orthosteric site, and the conformational dynamics of the activation process as a molecular switch linking these multiple sites. The model emerging from these studies paves the way for a new pharmacology based, first, upon the occurrence of an original mode of indirect allosteric modulation, distinct from a steric competition for a single and rigid binding site, and second, the design of drugs that specifically interact with privileged conformations of the receptor such as agonists, antagonists, and desensitizers. Research on nicotinic receptors is still at the forefront of understanding the mode of action of drugs on the nervous system. </jats:p><jats:p> Expected final online publication date for the Annual Review of Biochemistry , Volume 93 is June 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates. </jats:p>

<jats:p> Writing a career retrospective for this prestigious series is a huge challenge. Is my story really of that much interest? One thing that is different about my life in science is the heavy influence of the turmoil of the past century. Born in the US, raised in East Germany, and returning to the US relatively late in life, I experienced research under both suboptimal and privileged conditions. My scientific story, like the political winds that blew me from one continent to the next, involved shifts into different fields. For advice to young scientists, I would suggest: Don't be afraid to start something new, it pays to be persistent, and science is a passion. In addition to telling my own story, this article also provides the opportunity to express my gratitude to my trainees and colleagues and to convey my conviction that we have the best job on earth. </jats:p><jats:p> Expected final online publication date for the Annual Review of Biochemistry , Volume 93 is June 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates. </jats:p>

<jats:p> Cellular quality control systems sense and mediate homeostatic responses to prevent the buildup of aberrant macromolecules, which arise from errors during biosynthesis, damage by environmental insults, or imbalances in enzymatic and metabolic activity. Lipids are structurally diverse macromolecules that have many important cellular functions, ranging from structural roles in membranes to functions as signaling and energy-storage molecules. As with other macromolecules, lipids can be damaged (e.g., oxidized), and cells require quality control systems to ensure that nonfunctional and potentially toxic lipids do not accumulate. Ferroptosis is a form of cell death that results from the failure of lipid quality control and the consequent accumulation of oxidatively damaged phospholipids. In this review, we describe a framework for lipid quality control, using ferroptosis as an illustrative example to highlight concepts related to lipid damage, membrane remodeling, and suppression or detoxification of lipid damage via preemptive and damage-repair lipid quality control pathways. </jats:p><jats:p> Expected final online publication date for the Annual Review of Biochemistry , Volume 93 is June 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates. </jats:p>