Manuel Ascano, Jr., Ph.D.

Assistant Professor

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Faculty Appointments
Assistant Professor of Biochemistry Assistant Professor of Pathology, Microbiology and Immunology
Ph.D., Molecular Gen, Biochemistry, Microbiology, University of Cincinnati, Cincinnati, OhioB.S., Microbiology, University of Illinois, Urbana-Champaign, Illinois
Office Address
2215 Garland Avenue, 673C Light Hall
Nashville, TN 37232
Research Description
The flow of genetic information from DNA to RNA to protein requires the orchestration of specialized proteins that bind to and regulate RNAs. The human genome encodes for over 1,400 RNA-binding proteins, most of whose functions are unknown despite their importance during development and in specific human diseases. The processes by which RNA-binding proteins regulate RNA, collectively known as post-transcriptional gene regulation, permit cells to adapt rapidly to changing environmental cues such that gene expression programs, and thus cellular function, are fine-tuned. For example, post-transcriptional gene regulatory processes serve to mitigate the effects of deleterious stresses that can potentially usurp or disrupt gene expression in cases of bacterial or viral infection, when foreign nucleic acids are introduced into cells. The post-transcriptional mechanisms that prevent aberrant or pathogen gene expression, while still coordinating the expression of host-specific innate immune- and stress-activated genes, remains poorly understood.

My laboratory is currently focused on two research areas:

1) To identify and functionally characterize the critical RNA-binding proteins utilized by cells during periods of nucleic acid-induced stress and innate immune gene activation.

A key prerequisite for characterizing the function of RNA-binding proteins is to identify its stress-regulated binding targets. My laboratory utilizes RNA biochemistry and molecular biology, in conjunction with modern high-throughput technologies such as PAR-CLIP, to elucidate RNA-protein interactions and gene regulatory function at a transcriptome-wide level. As a complementary approach, we investigate the composition and function of RNA-binding protein complexes (ribonucleoprotein particles) that assemble on specific stress-induced host- or pathogen-encoded transcripts, to understand how such relationships are important for host-cell response and survival.

2) To characterize the components and signaling mechanism of a major cytosolic DNA-sensing pathway.

Detection of cytosolic DNA potently activates multiple signaling pathways leading to the transcriptional activation of interferon and stress-activated genes. Thus, the cellular response and gene expression changes associated with DNA-sensing is an ideal model for investigating stress-induced post-transcriptional gene regulatory processes. My laboratory focuses on the innate immune signaling pathway initiated by the DNA sensor and nucleotidyl transferase superfamily member cyclic GMP-AMP synthase, cGAS. Binding of cytosolic DNA to cGAS leads to its production of cyclic GMP-AMP (cGAMP), which I discovered to be the founding member of metazoan cyclical second messenger molecules containing mixed phosphodiester bonds (2',5' and 3',5'). We examine the mechanism of cGAS activation by structure-function and cell biological studies. My laboratory also investigates how natural and synthetic cyclic dinucleotides and related analogs promote innate immune gene activation through the only known cGAMP receptor, Stimulator of interferon genes (STING).
Research Keywords
Post-transcriptional gene regulation in innate immunity and cellular stress
Kashima R, Roy S, Ascano M, Martinez-Cerdeno V, Ariza-Torres J, Kim S, Louie J, Lu Y, Leyton P, Bloch KD, Kornberg TB, Hagerman PJ, Hagerman R, Lagna G, Hata A. Augmented noncanonical BMP type II receptor signaling mediates the synaptic abnormality of fragile X syndrome. Sci Signal. 2016; 9(431): ra58. PMID: 27273096, PII: 9/431/ra58, DOI: 10.1126/scisignal.aaf6060, ISSN: 1937-9145.

Kavanaugh G, Zhao R, Guo Y, Mohni KN, Glick G, Lacy ME, Hutson MS, Ascano M, Cortez D. Enhancer of Rudimentary Homolog Affects the Replication Stress Response through Regulation of RNA Processing. Mol. Cell. Biol [print-electronic]. 2015 Sep 9/1/2015; 35(17): 2979-90. PMID: 26100022, PMCID: PMC4525316, PII: MCB.01276-14, DOI: 10.1128/MCB.01276-14, ISSN: 1098-5549.

Gao P, Zillinger T, Wang W, Ascano M, Dai P, Hartmann G, Tuschl T, Deng L, Barchet W, Patel DJ. Binding-pocket and lid-region substitutions render human STING sensitive to the species-specific drug DMXAA. Cell Rep [print-electronic]. 2014 Sep 9/25/2014; 8(6): 1668-76. PMID: 25199835, PMCID: PMC4381552, PII: S2211-1247(14)00673-1, DOI: 10.1016/j.celrep.2014.08.010, ISSN: 2211-1247.

Spitzer J, Hafner M, Landthaler M, Ascano M, Farazi T, Wardle G, Nusbaum J, Khorshid M, Burger L, Zavolan M, Tuschl T. PAR-CLIP (Photoactivatable Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation): a step-by-step protocol to the transcriptome-wide identification of binding sites of RNA-binding proteins. Meth. Enzymol. 2014; 539: 113-61. PMID: 24581442, PMCID: PMC4180672, PII: B978-0-12-420120-0.00008-6, DOI: 10.1016/B978-0-12-420120-0.00008-6, ISSN: 1557-7988.

Wittkowski KM, Sonakya V, Bigio B, Tonn MK, Shic F, Ascano M, Nasca C, Gold-Von Simson G. A novel computational biostatistics approach implies impaired dephosphorylation of growth factor receptors as associated with severity of autism. Transl Psychiatry. 2014; 4: e354. PMID: 24473445, PMCID: PMC3905234, PII: tp2013124, DOI: 10.1038/tp.2013.124, ISSN: 2158-3188.

Gerstberger S, Hafner M, Ascano M, Tuschl T. Evolutionary conservation and expression of human RNA-binding proteins and their role in human genetic disease. Adv. Exp. Med. Biol. 2014; 825: 1-55. PMID: 25201102, PMCID: PMC4180674, DOI: 10.1007/978-1-4939-1221-6_1, ISSN: 0065-2598.

Gao P, Ascano M, Zillinger T, Wang W, Dai P, Serganov AA, Gaffney BL, Shuman S, Jones RA, Deng L, Hartmann G, Barchet W, Tuschl T, Patel DJ. Structure-function analysis of STING activation by c[G(2',5')pA(3',5')p] and targeting by antiviral DMXAA. Cell [print-electronic]. 2013 Aug 8/15/2013; 154(4): 748-62. PMID: 23910378, PMCID: PMC4386733, PII: S0092-8674(13)00894-5, DOI: 10.1016/j.cell.2013.07.023, ISSN: 1097-4172.

Nakanishi K, Ascano M, Gogakos T, Ishibe-Murakami S, Serganov AA, Briskin D, Morozov P, Tuschl T, Patel DJ. Eukaryote-specific insertion elements control human ARGONAUTE slicer activity. Cell Rep. 2013 Jun 6/27/2013; 3(6): 1893-900. PMID: 23809764, PMCID: PMC3757560, PII: S2211-1247(13)00288-X, DOI: 10.1016/j.celrep.2013.06.010, ISSN: 2211-1247.

Gao P, Ascano M, Wu Y, Barchet W, Gaffney BL, Zillinger T, Serganov AA, Liu Y, Jones RA, Hartmann G, Tuschl T, Patel DJ. Cyclic [G(2',5')pA(3',5')p] is the metazoan second messenger produced by DNA-activated cyclic GMP-AMP synthase. Cell [print-electronic]. 2013 May 5/23/2013; 153(5): 1094-107. PMID: 23647843, PMCID: PMC4382009, PII: S0092-8674(13)00522-9, DOI: 10.1016/j.cell.2013.04.046, ISSN: 1097-4172.

Ascano M, Gerstberger S, Tuschl T. Multi-disciplinary methods to define RNA-protein interactions and regulatory networks. Curr. Opin. Genet. Dev [print-electronic]. 2013 Feb; 23(1): 20-8. PMID: 23453689, PMCID: PMC3624891, PII: S0959-437X(13)00011-7, DOI: 10.1016/j.gde.2013.01.003, ISSN: 1879-0380.

Ascano M, Mukherjee N, Bandaru P, Miller JB, Nusbaum JD, Corcoran DL, Langlois C, Munschauer M, Dewell S, Hafner M, Williams Z, Ohler U, Tuschl T. FMRP targets distinct mRNA sequence elements to regulate protein expression. Nature [print-electronic]. 2012 Dec 12/20/2012; 492(7429): 382-6. PMID: 23235829, PMCID: PMC3528815, PII: nature11737, DOI: 10.1038/nature11737, ISSN: 1476-4687.

Ascano M, Hafner M, Cekan P, Gerstberger S, Tuschl T. Identification of RNA-protein interaction networks using PAR-CLIP. Wiley Interdiscip Rev RNA [print-electronic]. 2012 Mar; 3(2): 159-77. PMID: 22213601, PMCID: PMC3711140, DOI: 10.1002/wrna.1103, ISSN: 1757-7012.

Hafner M, Ascano M, Tuschl T. New insights in the mechanism of microRNA-mediated target repression. Nature structural & molecular biology. 2011 Nov; 18(11) Sect. 1181,2.

Mukherjee N, Corcoran DL, Nusbaum JD, Reid DW, Georgiev S, Hafner M, Ascano M, Tuschl T, Ohler U, Keene JD. Integrative regulatory mapping indicates that the RNA-binding protein HuR couples pre-mRNA processing and mRNA stability. Mol. Cell [print-electronic]. 2011 Aug 8/5/2011; 43(3): 327-39. PMID: 21723170, PMCID: PMC3220597, PII: S1097-2765(11)00421-7, DOI: 10.1016/j.molcel.2011.06.007, ISSN: 1097-4164.

Tian Y, Simanshu DK, Ascano M, Diaz-Avalos R, Park AY, Juranek SA, Rice WJ, Yin Q, Robinson CV, Tuschl T, Patel DJ. Multimeric assembly and biochemical characterization of the Trax-translin endonuclease complex. Nat. Struct. Mol. Biol [print-electronic]. 2011 Jun; 18(6): 658-64. PMID: 21552261, PMCID: PMC3109869, PII: nsmb.2069, DOI: 10.1038/nsmb.2069, ISSN: 1545-9985.

Hafner M, Landthaler M, Burger L, Khorshid M, Hausser J, Berninger P, Rothballer A, Ascano M, Jungkamp AC, Munschauer M, Ulrich A, Wardle GS, Dewell S, Zavolan M, Tuschl T. Transcriptome-wide identification of RNA-binding protein and microRNA target sites by PAR-CLIP. Cell. 2010 Apr 4/2/2010; 141(1): 129-41. PMID: 20371350, PMCID: PMC2861495, PII: S0092-8674(10)00245-X, DOI: 10.1016/j.cell.2010.03.009, ISSN: 1097-4172.

Tokhunts R, Singh S, Chu T, D'Angelo G, Baubet V, Goetz JA, Huang Z, Yuan Z, Ascano M, Zavros Y, Thérond PP, Kunes S, Dahmane N, Robbins DJ. The full-length unprocessed hedgehog protein is an active signaling molecule. J. Biol. Chem [print-electronic]. 2010 Jan 1/22/2010; 285(4): 2562-8. PMID: 19920144, PMCID: PMC2807313, PII: M109.078626, DOI: 10.1074/jbc.M109.078626, ISSN: 1083-351X.

Hafner M, Landthaler M, Burger L, Khorshid M, Hausser J, Berninger P, Rothballer A, Ascano M, Jungkamp AC, Munschauer M, Ulrich A, Wardle GS, Dewell S, Zavolan M, Tuschl T. PAR-CliP--a method to identify transcriptome-wide the binding sites of RNA binding proteins. J Vis Exp. 2010; (41): PMID: 20644507, PMCID: PMC3156069, PII: 2034, DOI: 10.3791/2034, ISSN: 1940-087X.

Farzan SF, Stegman MA, Ogden SK, Ascano M, Black KE, Tacchelly O, Robbins DJ. A quantification of pathway components supports a novel model of Hedgehog signal transduction. J. Biol. Chem [print-electronic]. 2009 Oct 10/16/2009; 284(42): 28874-84. PMID: 19717563, PMCID: PMC2781433, PII: M109.041608, DOI: 10.1074/jbc.M109.041608, ISSN: 1083-351X.

Farzan SF, Ascano M, Ogden SK, Sanial M, Brigui A, Plessis A, Robbins DJ. Costal2 functions as a kinesin-like protein in the hedgehog signal transduction pathway. Curr. Biol [print-electronic]. 2008 Aug 8/26/2008; 18(16): 1215-20. PMID: 18691888, PMCID: PMC2774813, PII: S0960-9822(08)00893-2, DOI: 10.1016/j.cub.2008.07.026, ISSN: 0960-9822.

Ogden SK, Casso DJ, Ascano M, Yore MM, Kornberg TB, Robbins DJ. Smoothened regulates activator and repressor functions of Hedgehog signaling via two distinct mechanisms. J. Biol. Chem [print-electronic]. 2006 Mar 3/17/2006; 281(11): 7237-43. PMID: 16423832, PMCID: PMC3677211, PII: M510169200, DOI: 10.1074/jbc.M510169200, ISSN: 0021-9258.

Ascano M, Robbins DJ. An intramolecular association between two domains of the protein kinase Fused is necessary for Hedgehog signaling. Mol. Cell. Biol. 2004 Dec; 24(23): 10397-405. PMID: 15542847, PMCID: PMC529051, PII: 24/23/10397, DOI: 10.1128/MCB.24.23.10397-10405.2004, ISSN: 0270-7306.

Ogden SK, Ascano M, Stegman MA, Robbins DJ. Regulation of Hedgehog signaling: a complex story. Biochem. Pharmacol. 2004 Mar 3/1/2004; 67(5): 805-14. PMID: 15104233, PMCID: PMC3659400, ISSN: 0006-2952.

Stegman MA, Goetz JA, Ascano M, Ogden SK, Nybakken KE, Robbins DJ. The Kinesin-related protein Costal2 associates with membranes in a Hedgehog-sensitive, Smoothened-independent manner. J. Biol. Chem [print-electronic]. 2004 Feb 2/20/2004; 279(8): 7064-71. PMID: 14645371, PMCID: PMC3659396, PII: M311794200, DOI: 10.1074/jbc.M311794200, ISSN: 0021-9258.

Ogden SK, Ascano M, Stegman MA, Suber LM, Hooper JE, Robbins DJ. Identification of a functional interaction between the transmembrane protein Smoothened and the kinesin-related protein Costal2. Curr. Biol. 2003 Nov 11/11/2003; 13(22): 1998-2003. PMID: 14614827, PMCID: PMC3711143, PII: S0960982203007462, ISSN: 0960-9822.

Ascano M, Nybakken KE, Sosinski J, Stegman MA, Robbins DJ. The carboxyl-terminal domain of the protein kinase fused can function as a dominant inhibitor of hedgehog signaling. Mol. Cell. Biol. 2002 Mar; 22(5): 1555-66. PMID: 11839821, PMCID: PMC134684, ISSN: 0270-7306.

Mukhopadhyay B, Johnson EF, Ascano M. Conditions for vigorous growth on sulfide and reactor-scale cultivation protocols for the thermophilic green sulfur bacterium chlorobium tepidum. Appl. Environ. Microbiol. 1999 Jan; 65(1): 301-6. PMID: 9872796, PMCID: PMC91019, ISSN: 1098-5336.

Available Postdoctoral Position Details
Posted: 9/11/2014
A postdoctoral position in RNA Biochemistry and Molecular Biology is available in my laboratory. The postdoc will be joining a new research group whose primary research interests are in understanding the post-transcriptional gene regulatory mechanisms employed by cells during periods of innate immune activation and cellular stress. The Ascano laboratory integrates traditional biochemistry, cell biology, and molecular biological disciplines with modern high-throughput and bioinformatics-oriented methodologies. Available research projects focus either on the delineation and functional characterization of specific RNA-protein interaction networks or on the biochemical dissection of a newly identified nucleic acid-stimulated innate immune signaling pathway. Interested candidates should submit by email a single PDF containing a cover letter, a CV with contact information for three references, and a very brief summary (1 page) of research accomplishments and potential research interests in my lab.