Author
Patrick R. Griffin
Other affiliations: Children's Hospital Los Angeles, University of Washington, National Institutes of Health ...read more
Bio: Patrick R. Griffin is an academic researcher from Scripps Research Institute. The author has contributed to research in topics: Nuclear receptor & Receptor. The author has an hindex of 79, co-authored 334 publications receiving 24755 citations. Previous affiliations of Patrick R. Griffin include Children's Hospital Los Angeles & University of Washington.
Papers published on a yearly basis
Papers
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TL;DR: A potent peptide aldehyde inhibitor has been developed and shown to prevent apoptotic events in vitro, suggesting that apopain/CPP32 is important for the initiation of apoptotic cell death.
Abstract: The protease responsible for the cleavage of poly(ADP-ribose) polymerase and necessary for apoptosis has been purified and characterized. This enzyme, named apopain, is composed of two subunits of relative molecular mass (M(r)) 17K and 12K that are derived from a common proenzyme identified as CPP32. This proenzyme is related to interleukin-1 beta-converting enzyme (ICE) and CED-3, the product of a gene required for programmed cell death in Caenorhabditis elegans. A potent peptide aldehyde inhibitor has been developed and shown to prevent apoptotic events in vitro, suggesting that apopain/CPP32 is important for the initiation of apoptotic cell death.
4,096 citations
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TL;DR: A heterotrimeric GTP-binding protein (G protein)-coupled receptor (GPC-R) of the pituitary and arcuate ventro-medial and infundibular hypothalamus of swine and humans was cloned and was shown to be the target of the GHSs.
Abstract: Small synthetic molecules termed growth hormone secretagogues (GHSs) act on the pituitary gland and the hypothalamus to stimulate and amplify pulsatile growth hormone (GH) release. A heterotrimeric GTP-binding protein (G protein)-coupled receptor (GPC-R) of the pituitary and arcuate ventro-medial and infundibular hypothalamus of swine and humans was cloned and was shown to be the target of the GHSs. On the basis of its pharmacological and molecular characterization, this GPC-R defines a neuroendocrine pathway for the control of pulsatile GH release and supports the notion that the GHSs mimic an undiscovered hormone.
2,064 citations
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TL;DR: Findings strongly suggest that Cdk5-mediated phosphorylation of PPARγ may be involved in the pathogenesis of insulin-resistance, and present an opportunity for development of an improved generation of anti-diabetic drugs throughPPARγ.
Abstract: Obesity induced in mice by high-fat feeding activates the protein kinase Cdk5 (cyclin-dependent kinase 5) in adipose tissues. This results in phosphorylation of the nuclear receptor PPARgamma (peroxisome proliferator-activated receptor gamma), a dominant regulator of adipogenesis and fat cell gene expression, at serine 273. This modification of PPARgamma does not alter its adipogenic capacity, but leads to dysregulation of a large number of genes whose expression is altered in obesity, including a reduction in the expression of the insulin-sensitizing adipokine, adiponectin. The phosphorylation of PPARgamma by Cdk5 is blocked by anti-diabetic PPARgamma ligands, such as rosiglitazone and MRL24. This inhibition works both in vivo and in vitro, and is completely independent of classical receptor transcriptional agonism. Similarly, inhibition of PPARgamma phosphorylation in obese patients by rosiglitazone is very tightly associated with the anti-diabetic effects of this drug. All these findings strongly suggest that Cdk5-mediated phosphorylation of PPARgamma may be involved in the pathogenesis of insulin-resistance, and present an opportunity for development of an improved generation of anti-diabetic drugs through PPARgamma.
786 citations
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TL;DR: A computer searching algorithm has been used to identify protein sequences in the Protein Information Resource (PIR) database with peptide mass information (mass map) obtained from proteolytic digests of proteins analyzed by microcapillary high-performance liquid chromatography electrospray ionization mass spectrometry.
691 citations
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Van Andel Institute1, Arizona State University2, University of Southern California3, SLAC National Accelerator Laboratory4, National University of Singapore5, Scripps Research Institute6, University of California, Los Angeles7, University of Toronto8, Vanderbilt University9, University of Wisconsin–Milwaukee10, Chinese Academy of Sciences11, Paul Scherrer Institute12, Trinity College, Dublin13, University of Chicago14, University of Konstanz15
TL;DR: The crystal structure of a constitutively active form of human rhodopsin bound to a pre-activated form of the mouse visual arrestin is determined by serial femtosecond X-ray laser crystallography and provides a basis for understanding GPCR-mediated arrestin-biased signalling.
Abstract: G-protein-coupled receptors (GPCRs) signal primarily through G proteins or arrestins. Arrestin binding to GPCRs blocks G protein interaction and redirects signalling to numerous G-protein-independent pathways. Here we report the crystal structure of a constitutively active form of human rhodopsin bound to a pre-activated form of the mouse visual arrestin, determined by serial femtosecond X-ray laser crystallography. Together with extensive biochemical and mutagenesis data, the structure reveals an overall architecture of the rhodopsin-arrestin assembly in which rhodopsin uses distinct structural elements, including transmembrane helix 7 and helix 8, to recruit arrestin. Correspondingly, arrestin adopts the pre-activated conformation, with a similar to 20 degrees rotation between the amino and carboxy domains, which opens up a cleft in arrestin to accommodate a short helix formed by the second intracellular loop of rhodopsin. This structure provides a basis for understanding GPCR-mediated arrestin-biased signalling and demonstrates the power of X-ray lasers for advancing the frontiers of structural biology.
672 citations
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TL;DR: Silver staining allows a substantial shortening of sample preparation time and may, therefore, be preferable over Coomassie staining, and this work removes a major obstacle to the low-level sequence analysis of proteins separated on polyacrylamide gels.
Abstract: Proteins from silver-stained gels can be digested enzymatically and the resulting peptides analyzed and sequenced by mass spectrometry. Standard proteins yield the same peptide maps when extracted from Coomassie- and silver-stained gels, as judged by electrospray and MALDI mass spectrometry. The low nanogram range can be reached by the protocols described here, and the method is robust. A silver-stained one-dimensional gel of a fraction from yeast proteins was analyzed by nanoelectrospray tandem mass spectrometry. In the sequencing, more than 1000 amino acids were covered, resulting in no evidence of chemical modifications due to the silver staining procedure. Silver staining allows a substantial shortening of sample preparation time and may, therefore, be preferable over Coomassie staining. This work removes a major obstacle to the low-level sequence analysis of proteins separated on polyacrylamide gels.
8,437 citations
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TL;DR: A new computer program, Mascot, is presented, which integrates all three types of search for protein identification by searching a sequence database using mass spectrometry data, and the scoring algorithm is probability based.
Abstract: Several algorithms have been described in the literature for protein identification by searching a sequence database using mass spectrometry data. In some approaches, the experimental data are peptide molecular weights from the digestion of a protein by an enzyme. Other approaches use tandem mass spectrometry (MS/MS) data from one or more peptides. Still others combine mass data with amino acid sequence data. We present results from a new computer program, Mascot, which integrates all three types of search. The scoring algorithm is probability based, which has a number of advantages: (i) A simple rule can be used to judge whether a result is significant or not. This is particularly useful in guarding against false positives. (ii) Scores can be compared with those from other types of search, such as sequence homology. (iii) Search parameters can be readily optimised by iteration. The strengths and limitations of probability-based scoring are discussed, particularly in the context of high throughput, fully automated protein identification.
8,195 citations
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TL;DR: The occurrence of ghrelin in both rat and human indicates that GH release from the pituitary may be regulated not only by hypothalamic GHRH, but also by ghrelIn, a peptide specifically releases GH both in vivo and in vitro.
Abstract: Small synthetic molecules called growth-hormone secretagogues (GHSs) stimulate the release of growth hormone (GH) from the pituitary. They act through GHS-R, a G-protein-coupled receptor for which the ligand is unknown. Recent cloning of GHS-R strongly suggests that an endogenous ligand for the receptor does exist and that there is a mechanism for regulating GH release that is distinct from its regulation by hypothalamic growth-hormone-releasing hormone (GHRH). We now report the purification and identification in rat stomach of an endogenous ligand specific for GHS-R. The purified ligand is a peptide of 28 amino acids, in which the serine 3 residue is n-octanoylated. The acylated peptide specifically releases GH both in vivo and in vitro, and O-n-octanoylation at serine 3 is essential for the activity. We designate the GH-releasing peptide 'ghrelin' (ghre is the Proto-Indo-European root of the word 'grow'). Human ghrelin is homologous to rat ghrelin apart from two amino acids. The occurrence of ghrelin in both rat and human indicates that GH release from the pituitary may be regulated not only by hypothalamic GHRH, but also by ghrelin.
8,073 citations
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TL;DR: Mutation of the active site of caspase-9 attenuated the activation of cazase-3 and cellular apoptotic response in vivo, indicating that casp enzyme-9 is the most upstream member of the apoptotic protease cascade that is triggered by cytochrome c and dATP.
7,231 citations
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TL;DR: The approach described in this manuscript provides a convenient method to interpret tandem mass spectra with known sequences in a protein database.
6,317 citations