Peter Lengyel

Bio: Peter Lengyel is an academic researcher from Yale University. The author has contributed to research in topics: Interferon & RNA. The author has an hindex of 52, co-authored 140 publications receiving 8097 citations. Previous affiliations of Peter Lengyel include University of Arizona & New York University.

Synthetic polynucleotides and the amino acid code. V.

Abstract: This report from the Department of Biochemistry at the New York University School of Medicine examines the agreement found between experimentally determined letters of the genetic code and amino acid replacement methods in nitrous acid mutants of the tobacco mosaic virus (TMV).

Interferon action: RNA cleavage pattern of a (2'-5')oligoadenylate--dependent endonuclease.

Abstract: One of the mediators of interferon action is a latent endoribonuclease (ribonuclease L) that is activated by (2'-5')oligoadenylates Among the homopolymers of the four common ribonucleotides, activated ribonuclease L degrades at an appreciable rate only polyuridylic acid In two natural RNA's tested the most frequent ribonuclease L cleavages occur after UA, UG, and UU (A, adenine; U, uracil; and G, guanine) and much less frequent cleavages after CA and AC (C, cytosine)

Interferon, double-stranded RNA, and protein phosphorylation

Abstract: We reported earlier that the addition of double-stranded RNA and ATP increases the endonuclease activity more in an extract of Ehrlich ascites tumor cells which have been treated with an interferon preparation than in a comparable extract from control cells. We report here that the addition of double-stranded RNA to an extract from Ehrlich ascites tumor cells which have been treated with an interferon preparation [or with the interferon inducer poly(I)-poly(C)] promotes the phosphorylation by [gamma-32P]ATP of at least two proteins: P1 (molecular weight of 64,000) and P2 (molecular weight of 37,000). Double-stranded RNA also promotes the phosphorylation of at least one (i.e., P1) of these two proteins in an extract from cells which have not been treated with interferon, but the extent of phosphorylation is much smaller. Double-stranded RNA which has been degraded by RNase III, or DNA, does not promote the phosphorylation.

Accumulation of an mRNA and protein in interferon-treated Ehrlich ascites tumour cells.

Abstract: INTERFERONS are glycoproteins which are synthesised by various vertebrate cells in response to virus infection or some other stimuli. They are secreted and then interact with other cells and convert these into an antiviral state, in which the multiplication of viruses is impaired1. It is thought that transcription and translation are required for the establishment of the antiviral state as actinomycin D or inhibitors of protein synthesis, suitably administered, prevent or delay the effect2,3. Results with enucleated cells also support this idea4. We show here that treatment of Ehrlich ascites tumour (EAT) cells with highly purified interferon results in the accumulation of a particular mRNA and the corresponding protein within the cells. However, we have not yet identified the function of the induced protein.

How cells respond to interferons

Abstract: Interferons play key roles in mediating antiviral and antigrowth responses and in modulating immune response. The main signaling pathways are rapid and direct. They involve tyrosine phosphorylation and activation of signal transducers and activators of transcription factors by Janus tyrosine kinases at the cell membrane, followed by release of signal transducers and activators of transcription and their migration to the nucleus, where they induce the expression of the many gene products that determine the responses. Ancillary pathways are also activated by the interferons, but their effects on cell physiology are less clear. The Janus kinases and signal transducers and activators of transcription, and many of the interferon-induced proteins, play important alternative roles in cells, raising interesting questions as to how the responses to the interferons intersect with more general aspects of cellular physiology and how the specificity of cytokine responses is maintained.

The 3′-Terminal Sequence of Escherichia coli 16S Ribosomal RNA: Complementarity to Nonsense Triplets and Ribosome Binding Sites

Abstract: With a stepwise degradation and terminal labeling procedure the 3′-terminal sequence of E. coli 16S ribosomal RNA is shown to be Pyd-A-C-C-U-C-C-U-U-AOH. It is suggested that this region of the RNA is able to interact with mRNA and that the 3′-terminal U-U-AOH is involved in the termination of protein synthesis through base-pairing with terminator codons. The sequence A-C-C-U-C-C could recognize a conserved sequence found in the ribosome binding sites of various coliphage mRNAs; it may thus be involved in the formation of the mRNA·30S subunit complex.

Antiviral Actions of Interferons

Abstract: Tremendous progress has been made in understanding the molecular basis of the antiviral actions of interferons (IFNs), as well as strategies evolved by viruses to antagonize the actions of IFNs. Furthermore, advances made while elucidating the IFN system have contributed significantly to our understanding in multiple areas of virology and molecular cell biology, ranging from pathways of signal transduction to the biochemical mechanisms of transcriptional and translational control to the molecular basis of viral pathogenesis. IFNs are approved therapeutics and have moved from the basic research laboratory to the clinic. Among the IFN-induced proteins important in the antiviral actions of IFNs are the RNA-dependent protein kinase (PKR), the 2',5'-oligoadenylate synthetase (OAS) and RNase L, and the Mx protein GTPases. Double-stranded RNA plays a central role in modulating protein phosphorylation and RNA degradation catalyzed by the IFN-inducible PKR kinase and the 2'-5'-oligoadenylate-dependent RNase L, respectively, and also in RNA editing by the IFN-inducible RNA-specific adenosine deaminase (ADAR1). IFN also induces a form of inducible nitric oxide synthase (iNOS2) and the major histocompatibility complex class I and II proteins, all of which play important roles in immune response to infections. Several additional genes whose expression profiles are altered in response to IFN treatment and virus infection have been identified by microarray analyses. The availability of cDNA and genomic clones for many of the components of the IFN system, including IFN-alpha, IFN-beta, and IFN-gamma, their receptors, Jak and Stat and IRF signal transduction components, and proteins such as PKR, 2',5'-OAS, Mx, and ADAR, whose expression is regulated by IFNs, has permitted the generation of mutant proteins, cells that overexpress different forms of the proteins, and animals in which their expression has been disrupted by targeted gene disruption. The use of these IFN system reagents, both in cell culture and in whole animals, continues to provide important contributions to our understanding of the virus-host interaction and cellular antiviral response.