Dpto. Bioquímica y Biología Molecular y Fisiología - Capítulos de monografías https://uvadoc.uva.es/handle/10324/1214 2026-04-17T11:44:45Z 2026-04-17T11:44:45Z Alonso, Andrés E Nunes-Xavier, Caroline Bayón Prieto, Yolanda Pulido, Rafael https://uvadoc.uva.es/handle/10324/73883 2025-01-15T20:00:53Z 2016-01-01T00:00:00Z

In higher eukaryotes, the Tyr phosphorylation status of cellular proteins results from the coordinated action of Protein Tyrosine Kinases (PTKs) and Protein Tyrosine Phosphatases (PTPs). PTPs have emerged as highly regulated enzymes with diverse substrate specificity, and proteins with Tyr-dephosphorylation or Tyr-dephosphorylation-like properties can be clustered as the PTPome. This includes proteins from the PTP superfamily, which display a Cys-based catalytic mechanism, as well as enzymes from other gene families (Asp-based phosphatases, His-based phosphatases) that have converged in protein Tyr-dephosphorylation-related functions by using non-Cys-based catalytic mechanisms. Within the Cys-based members of the PTPome, classical PTPs dephosphorylate specific phosphoTyr (pTyr) residues from protein substrates, whereas VH1-like dual-specificity PTPs dephosphorylate pTyr, pSer, and pThr residues, as well as nonproteinaceous substrates, including phosphoinositides and phosphorylated carbohydrates. In addition, several PTPs have impaired catalytic activity as a result of amino acid substitutions at their active sites, but retain regulatory functions related with pTyr signaling. As a result of their relevant biological activity, many PTPs are linked to human disease, including cancer, neurodevelopmental, and metabolic diseases, making these proteins important drug targets and molecular markers in the clinic. Here, a brief overview on the biochemistry and physiology of the different groups of proteins that belong to the mammalian PTPome is presented.

2016-01-01T00:00:00Z Girotti ., Alessandra González Valdivieso, Juan Alonso Sampedro, Irene Escalera Anzola, Sara Ramos Díez, Sandra Arias Vallejo, Francisco Javier https://uvadoc.uva.es/handle/10324/73863 2025-01-17T07:12:44Z 2022-01-01T00:00:00Z

Particulate material is more efficient in eliciting immune responses. Here we describe the production of micro- and nanospheres formed by protein muNS-Mi from avian reoviruses, loaded with foreign epitopes for their use as vaccines.

2022-01-01T00:00:00Z Nieves-Cintrón, Madeline Tajada Esteban, Sendoa Santana, Luis Fernando Navedo, Manuel F. https://uvadoc.uva.es/handle/10324/65813 2024-12-16T12:23:36Z 2018-01-01T00:00:00Z

This chapter provides an overview of the basic concepts behind Total Internal Reflection Fluorescence Microscopy (TIRFM), and its application to the study of the function and regulation of plasmalemmal Ca2+-permeable channels in vascular smooth muscle. TIRFM utilizes an evanescent wave to selectively excite fluorophores in regions of a sample directly adjacent to the glass coverslip-buffer interface. The principles at the heart of TIRFM are based on the laws of refraction of light and properties of the refractive media. TIRFM relies on the ability to introduce light at angles exceeding a critical angle. A particular innovative use of TIRFM has been on the recording of Ca2+ signals produced by the opening of Ca2+-permeable channels at the plasma membrane of a cell, including vascular smooth muscle cells. The quality of vascular smooth muscle cells is critical for successful recording of sparklets using TIRFM. Single vascular smooth muscle cells can be obtained by enzymatic digestion of freshly dissected arteries from different vascular beds.

2018-01-01T00:00:00Z Pérez García, María Teresa López López, José Ramón González Martínez, Constancio https://uvadoc.uva.es/handle/10324/25773 2025-03-03T10:20:44Z 1999-01-01T00:00:00Z

La función principal del aparato respiratorio es mantener las presiones parciales normales de02 y C02 junto con la concentración de H•. Esta importante fun­ ción reguladora constituye la función homeostática del sistema respiratorio, y se consigue ajustando la ventilación a las necesidades metabólicas de consumo de 02 y producción de C02 del organismo. A pesar de las amplias variaciones en los requerimientos de cap­ tación de 02 y eliminación de C021 la P02 y la PC02 arteriales se mantienen normalmente dentro de unos márgenes muy estrechos,debido a la existencia de una regulación compleja de la ventilación mediante una je­ rarquía de sistemas de control. Además,el aparato res­ piratorio participa en otras funciones no homeostáti­ cas (o funciones conductuales) de carácter voluntario, tales como la fonación.

1999-01-01T00:00:00Z López López, José Ramón Peers, Chris https://uvadoc.uva.es/handle/10324/25086 2021-06-24T07:37:04Z 1997-01-01T00:00:00Z

The carotid body (CB) chemoreceptor cells, m spite of their neural origin, were considered nonexcitable until the late 1980's. The remarkable complexity of the organ, together . with the small size of type I cells, represented a limitation for conventional intracellular microelectrode recordings, making a definitive electrophysiological study problematic. The neurochemical approach used during the early l980's, following the stimulus-secretion model established in other neurosecretory systems, suggested an important role for the plasma membrane of type I cells in the hypoxic chemotransduction process. Development of iso­ lated type I cell cultures, together with the use of the patch-damp technique, have brought direct evidence in support of this idea.1 We now have a general picture about the electrical properties of these cells, and their excitable character is unequivocally established; they pos­ sess voltage-dependent ion channels and they are capable of firing action potentials.Al­ though there is a general agreement in the literature about the basic facts, the details are far from being clear. The role of ionic currents in the transduction process by type I cells has been a matter of discussion, and differences in the results reported by different laboratories are evident. In most of the cases the differences could be interpreted on basis of the fact that . either cells from different species or at different stages of development have been studied, but in sorne cases, the differences have led to the proposal of different hypotheses about the mechanisms of chemotransduction.

1997-01-01T00:00:00Z Obeso Cáceres, Ana María de la Luz Rocher Martín, María Asunción López López, José Ramón González Martínez, Constancio https://uvadoc.uva.es/handle/10324/25055 2025-03-03T10:26:56Z 1996-01-01T00:00:00Z

The pívotal role of íntracellular free [Ca2+] fluctuatíons in the control of cellular functíons such as contraction and secretíon, íncludíng the release of neurotransmítters, was recognized many decades ago (see Rubín, 1982). More recently, the list of cellular functíons tríggered or modulated by the levels of Ca2+¡ has grown enormously. Addítional functíons regulated by [Ca2+)¡ include neuronal excítabílity, synaptic plastícíty, gene ex­ pressíon, cellular metabolísm, cell dívísíon and dífferentíatíon, and programmed cell dead (Míller, 1991; Clapham, 1995). Parallelíng the growth in this líst of Ca2+-controlled func­ tíons, a multíplicity of cellular mechanísms aimed at maintaining resting free [Ca2+)¡ in the range of l 00 nM for most cells has been described, allowing increases in Ca2+¡ levels that are specific in their magnitude, time course and spatial distributíon, accordíng to the cell function activated (Toescu, 1995). Since Ca2+ cannot be metabolized, cells regulate theír cytoplasmic levels of free Ca2+ through numerous bínding proteíns and influx and efflux mechanisms (Fíg 1). Ca2+ ínflux to cell cytoplasm from the extracellular milieu occurs vía voltage or receptor operated channels or vía yet ill-defined capacítatíve pathways; the Na+/Ca 2+ exchanger can also produce in sorne círcumstances net ínflux of Ca2+ (Míller, 1991; Clapham, 1995). Ca2+ ef­ flux to the extracellular space occurs against electrochemical gradíents, and thereby the pumpíng out of Ca2+ is directly (Caz+ pump) or indirectly (Na+/Ca2+) coupled to the hy­ drolysis of ATP.

1996-01-01T00:00:00Z González Martínez, Constancio Rocher Martín, María Asunción Obeso Cáceres, Ana María de la Luz López López, José Ramón García-Sancho Martín, Francisco Javier https://uvadoc.uva.es/handle/10324/24947 2025-03-03T10:18:03Z 1993-01-01T00:00:00Z

The carotid body (CB) was defined as a sensory organ by De Castro in 1928. Two years later, Heymanns and coworkers demostrated that the organ was sensitive to alterations in blood gases and pH, in such a way that a decrease in blood P02 or pH or an increase in blood PC02 produced activation of the CB and, reflexely, hyperventilation. De Castro postulated that glomus cells were the sensor structures and that they should release sorn substance to transmit the stimulus to the sensory nerve endings (De Castro, 1928). De Castro's point of view, was widely accepted, and therefore the CB was considered a secondary sensory receptor. As a consequence, the principal aims of many workers in the chemoreception field have been to define the nature of the sensing mechanims ( sensory transduction process ) and to identify the substances released by chern cells.

1993-01-01T00:00:00Z González Martínez, Constancio Rocher Martín, María Asunción Obeso Cáceres, Ana María de la Luz López López, José Ramón López Barneo, José Herreros Guilarte, Benito https://uvadoc.uva.es/handle/10324/24835 2025-03-03T10:27:36Z 1990-01-01T00:00:00Z

Tbe receptor complex in the carotid body (CB) is formed by clusters of type 1 cells that are connected synaptically to the endings of the chemo­ sensory fibers of the carotid sinus nerve (CSN), partia lly covered by type JI cells, and surrounded by a dense net of fenestrated capillaries (1). Sorne aspects of CB chemoreceptor physiology such as the identity of adequate stimulus, the characteristics of the receptor response to the dif­ ferent stimuli, and the reflex responses elicited upon CB stimulation are well known. Contrary to this, the basic mechanisms operating in this re­ ceptor are not completely understood (2). It has been proposed that low Po2 will decrease the ATP leveIs in the chemoreceptor or type 1cells and that this decrease in ATP will trigger the release of neurotransm itters capable of activating the sensory nerve endings. However, there is no proposal on how the decrease in ATP levels can activate the release process. It has been proposed also that high Pco2 and/or low pH in blood will increase the intracellular H+ concentration and that it will result i n in­ creased intracellu lar Ca2 + in type 1 cells and in the release of transmitters. Once again , there is no proposal on the mechanisms by which the increase in H+ can produce the increased Ca2+ concentration in type I cells (2,3).

1990-01-01T00:00:00Z Calvo Rodríguez, María Villalobos Jorge, Carlos Núñez Llorente, Lucía https://uvadoc.uva.es/handle/10324/21837 2021-06-23T09:53:46Z 2015-01-01T00:00:00Z

Intracellular Ca2+ is involved in control of a large variety of cell functions including apoptosis and neuron cell death. For example, intracellular Ca2+ overload is critical in neuron cell death induced by excitotoxicity. Thus, single cell monitoring of intracellular Ca2+ concentration ([Ca2+]cyt) in neurons concurrently with apoptosis and neuron cell death is widely required. Procedures for culture and preparation of primary cultures of hippocampal rat neurons and fluorescence imaging of cytosolic Ca2+ concentration in Fura2/AM-loaded neurons are described. We also describe a method for apoptosis detection by immunofluorescence imaging. Finally, a simple method for concurrent measurements of [Ca2+]cyt and apoptosis in the same neurons is described.

2015-01-01T00:00:00Z Ganfornina Álvarez, María Dolores Sánchez Romero, Diego Greene, Lesley H. Flower, Darren R. https://uvadoc.uva.es/handle/10324/6262 2021-06-23T09:53:45Z 2005-01-01T00:00:00Z

Lipocalins are remarkable in their diversity, as manifest at the levels of protein sequence and protein function. At the level of 3-dimensional structure, however, they are very similar. The lipocalins are also part of a larger protein superfamily: the calycins, which also includes the fatty acid binding proteins, adivins, a group of metalloproteinase inhibitors, and triabin. The superfamily is characterised by a similar structure (a repeated +1 topology B-barrel) and by the conservation of a remarkable structural signature. In this review, both of these aspects are explored.

2005-01-01T00:00:00Z Ganfornina Álvarez, María Dolores Kayser, Hartmut Sánchez Romero, Diego https://uvadoc.uva.es/handle/10324/6260 2021-06-23T09:53:44Z 2005-01-01T00:00:00Z

The number of sequenced arthropodan lipocalins adds up to over eighty (see Table 1). From our currently fragmented knowledge of arthopodan genomes, the last common ancestor of this phylum is proposed to possess two lipocalins (see Chapter 3). Intra-lineage duplications enlarged the number of lipocalins, with some large family expansions occurring independently in blood-feeding insects and arachnids. Most arthopodan lipocalins share the common signature and structural properties with the rest of the family. They are single modular proteins of around 200 amino acids that fold tightly in a B-barrel with potential for binding small hydrophobic molecules in a central pocket.

2005-01-01T00:00:00Z Sánchez Romero, Diego Ganfornina Álvarez, María Dolores Gutiérrez, Gabriel Gauthier-Jauneau, Anne-Christine Risler, Jean-Loup Salier, Jean-Philippe https://uvadoc.uva.es/handle/10324/6219 2021-06-23T09:53:42Z 2005-01-01T00:00:00Z

As extensively detailed elsewhere in this book, lipocalins exibit three characteristic features, which include: (i) an unusually low amino acid sequence similarity (typically 15-25% between paralogs) (ii) a highly conserved protein tertiary structure, and (iii) a similar arrangement of exons and introns in the coding sequence of their genes. These shared protein and gene features are overwhelming arguments for the existence of a single lipocalin ancestral gene that once extended into a family. The ancestral gene appears to have arisen in a group of bacteria, and possibly was inherited by eukaryotes as a result of genome fusion (see Chapter 4). Given this hypothetical beginning, lipocalins are expected to be found in all descendants of the eukaryotic common ancestor. Currently, and aside of prokaryotes, bona fide lipocalin have been recovered from a protoctist, a fungus, several plants, a nematode, several arthropods, a tunicate, a cephalochordate, and many examples of chordates. This review will first focus on the structure of lipocalin genes in eukaryotes, and then on our current view of the evolutionary hostory of this family.

2005-01-01T00:00:00Z