Author
Ricardo A. Bernal
Other affiliations: Laboratory of Molecular Biology, University of Texas at Austin, Purdue University
Bio: Ricardo A. Bernal is an academic researcher from University of Texas at El Paso. The author has contributed to research in topics: Chaperonin & Protein folding. The author has an hindex of 21, co-authored 38 publications receiving 1827 citations. Previous affiliations of Ricardo A. Bernal include Laboratory of Molecular Biology & University of Texas at Austin.
Topics: Chaperonin, Protein folding, Thermus thermophilus, GroEL, ATP synthase
Papers
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TL;DR: It is shown that mice with a targeted disruption in the Braf gene die of vascular defects during mid-gestation, and this work provides the first genetic evidence for an essential role of a Raf gene in the regulation of programmed cell death.
Abstract: Tyrosine kinase growth factor receptors and Ras/Raf/MEK/MAPK signalling have been implicated in the suppression1–3 as well as augmentation of programmed cell death4. In addition, a Ras-independent role for Raf as a suppressor of programmed cell death has been suggested by the recent finding that Craf1 interacts with members of the Bcl-2 family at mitochondrial membranes5. However, genetic studies of C elegans6 and Drosophila7, as well as the targeted mutagenesis of the murine Araf gene8, have failed to support such a role. Here we show that mice with a targeted disruption in the Braf gene die of vascular defects during mid-gestation. Braf−/− embryos, unlike Araf−/−8 or Craf1−/− embryos (L.W. et al., unpublished), show an increased number of endothelial precursor cells, dramatically enlarged blood vessels and apoptotic death of differentiated endothelial cells. These results establish Braf as a critical signalling factor in the formation of the vascular system and provide the first genetic evidence for an essential role of a Raf gene in the regulation of programmed cell death.
321 citations
TL;DR: It is shown that rotary adenosine triphosphatases (ATPases)/synthases from Thermus thermophilus and Enterococcus hirae can be maintained intact with membrane and soluble subunit interactions preserved in vacuum and can link specific lipid and nucleotide binding with distinct regulatory roles.
Abstract: The ability of electrospray to propel large viruses into a mass spectrometer is established and is rationalized by analogy to the atmospheric transmission of the common cold. Much less clear is the fate of membrane-embedded molecular machines in the gas phase. Here we show that rotary adenosine triphosphatases (ATPases)/synthases from Thermus thermophilus and Enterococcus hirae can be maintained intact with membrane and soluble subunit interactions preserved in vacuum. Mass spectra reveal subunit stoichiometries and the identity of tightly bound lipids within the membrane rotors. Moreover, subcomplexes formed in solution and gas phases reveal the regulatory effects of nucleotide binding on both ATP hydrolysis and proton translocation. Consequently, we can link specific lipid and nucleotide binding with distinct regulatory roles.
249 citations
TL;DR: Analgorithm has been developed for placing three-dimensional atomic structures into appropriately scaled cryoelectron microscopy maps and the best remaining fit is clearly superior to any of the others.
209 citations
TL;DR: The crystal structure of the peripheral stalk of the A-type ATPase/synthase from Thermus thermophilus, which contains a heterodimeric right-handed coiled coil, a protein fold never observed before, is determined and fitted into the 23 Å resolution EM density of the intact A-ATPase complex.
Abstract: The crystal structure of the peripheral stalk of the A-type ATPase/synthase (A-ATPase) from Thermus thermophilus reveals a heterodimeric right-handed coiled coil, a protein fold never observed before. Fitting of the stalk structure into the EM density of intact A-ATPase provides the most complete composite model so far.
95 citations
TL;DR: It is demonstrated that the new gene, referred to as 3pK (for chromosome 3p kinase), in fact encodes a mitogen-activated protein kinase-regulated protein serine-threonine kinase with a novel substrate specificity.
Abstract: NotI linking clones, localized to the human chromosome 3p21.3 region and homozygously deleted in small cell lung cancer cell lines NCI-H740 and NCI-H1450, were used to search for a putative tumor suppressor gene(s). One of these clones, NL1G210, detected a 2.5-kb mRNA in all examined human tissues, expression being especially high in the heart and skeletal muscle. Two overlapping cDNA clones containing the entire open reading frame were isolated from a human heart cDNA library and fully characterized. Computer analysis and a search of the GenBank database to reveal high sequence identity of the product of this gene to serine-threonine kinases, especially to mitogen-activated protein kinase-activated protein kinase 2, a recently described substrate of mitogen-activated kinases. Sequence identitiy was 72% at the nucleotide level and 75% at the amino acid level, strongly suggesting that this protein is a serine-threonine kinase. Here we demonstrate that the new gene, referred to as 3pK (for chromosome 3p kinase), in fact encodes a mitogen-activated protein kinase-regulated protein serine-threonine kinase with a novel substrate specificity.
93 citations
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28 Jul 2005
TL;DR: PfPMP1）与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
TL;DR: Nonenzymatic mechanisms that impact MAP kinase functions and findings from gene disruption studies are highlighted and particular emphasis is on ERK1/2.
Abstract: Mitogen-activated protein (MAP) kinases comprise a family of ubiquitous proline-directed, protein-serine/threonine kinases, which participate in signal transduction pathways that control intracellular events including acute responses to hormones and major developmental changes in organisms. MAP kinases lie in protein kinase cascades. This review discusses the regulation and functions of mammalian MAP kinases. Nonenzymatic mechanisms that impact MAP kinase functions and findings from gene disruption studies are highlighted. Particular emphasis is on ERK1/2.
4,040 citations
TL;DR: Data demonstrate that BAY 43-9006 is a novel dual action RAF kinase and VEGFR inhibitor that targets tumor cell proliferation and tumor angiogenesis.
Abstract: The RAS/RAF signaling pathway is an important mediator of tumor cell proliferation and angiogenesis. The novel bi-aryl urea BAY 43-9006 is a potent inhibitor of Raf-1, a member of the RAF/MEK/ERK signaling pathway. Additional characterization showed that BAY 43-9006 suppresses both wild-type and V599E mutant BRAF activity in vitro. In addition, BAY 43-9006 demonstrated significant activity against several receptor tyrosine kinases involved in neovascularization and tumor progression, including vascular endothelial growth factor receptor (VEGFR)-2, VEGFR-3, platelet-derived growth factor receptor beta, Flt-3, and c-KIT. In cellular mechanistic assays, BAY 43-9006 demonstrated inhibition of the mitogen-activated protein kinase pathway in colon, pancreatic, and breast tumor cell lines expressing mutant KRAS or wild-type or mutant BRAF, whereas non-small-cell lung cancer cell lines expressing mutant KRAS were insensitive to inhibition of the mitogen-activated protein kinase pathway by BAY 43-9006. Potent inhibition of VEGFR-2, platelet-derived growth factor receptor beta, and VEGFR-3 cellular receptor autophosphorylation was also observed for BAY 43-9006. Once daily oral dosing of BAY 43-9006 demonstrated broad-spectrum antitumor activity in colon, breast, and non-small-cell lung cancer xenograft models. Immunohistochemistry demonstrated a close association between inhibition of tumor growth and inhibition of the extracellular signal-regulated kinases (ERKs) 1/2 phosphorylation in two of three xenograft models examined, consistent with inhibition of the RAF/MEK/ERK pathway in some but not all models. Additional analyses of microvessel density and microvessel area in the same tumor sections using antimurine CD31 antibodies demonstrated significant inhibition of neovascularization in all three of the xenograft models. These data demonstrate that BAY 43-9006 is a novel dual action RAF kinase and VEGFR inhibitor that targets tumor cell proliferation and tumor angiogenesis.
3,749 citations
TL;DR: This review focuses on the biochemical components and regulation of mammalian stress-regulated mitogen-activated protein kinase (MAPK) pathways, and the nuclear factor-kappa B pathway, a second stress signaling paradigm.
Abstract: The molecular details of mammalian stress-activated signal transduction pathways have only begun to be dissected. This, despite the fact that the impact of these pathways on the pathology of chroni...
3,338 citations
TL;DR: All known MAPK module kinases from yeast to humans are defined, what is known about their regulation, defined MAPK substrates, and the function of MAPK in cell physiology are defined.
Abstract: Widmann, Christian, Spencer Gibson, Matthew B. Jarpe, and Gary L. Johnson. Mitogen-Activated Protein Kinase: Conservation of a Three-Kinase Module From Yeast to Human. Physiol. Rev. 79: 143–180, 19...
2,669 citations