Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology > Guru Rao

Guru Rao

Guru Rao


Structure-function relationships of plant proteins
Protein-protein interactions in plant signal transduction
Protein engineering

1210 Molecular Biology Building
Dept. of Biochemistry, Biophysics & Molecular Biology
Iowa State University
Ames, IA 50011

Lab #0049
Roy J Carver Co-labs
Ames, Iowa 50011-3650

Phone: (515) 294-6116

Ph.D., Biochemistry, University of Mysore, India, 1981
Postdoctoral Fellow, Case Western University, 1980-1983
Research Assistant Professor, University of South Carolina (Columbia, SC) 1983-87

Research Interests

Our research interests in protein science are broad, with an emphasis on the biochemical characterization of proteins to establish structure-activity relationships, protein engineering for altering protein function, protein folding, protein stability and protein-protein interactions. As the genome sequencing projects ‘unravel’ the primary structure of proteins, the crux of the issue becomes not the sequence per se but the characterization of proteins (i.e. post-translational modifications) and establishing function not only in isolation but through a network of interactions. Elucidation of the signal transduction pathways is expected to provide key insights into strategies to produce grain for food, feed and renewable fuels.

Signal transduction in plants
1. Cell surface receptor-mediated perception of signals is a common theme among living organisms. In animals, cellular signaling occurs predominantly through tyrosine kinase activity. In contrast, in plants, all available information indicates that serine/threonine kinase activity is exclusively used in signal transduction. One member of the ser/thr receptor-like kinase (RLK) family in plants is crinkly4 (CR4). The crinkly4 gene, encodes a tumor necrosis factor like (TNFR-like) receptor kinase CR4, which has been suggested to participate in an as yet unidentified ligand-induced signal for aleurone differentiation in maize seeds (Becraft et al., 1996). The homolog in Arabidopsis is designated as ACR4. The objectives in my research program are to apply biochemical and biophysical techniques to understand the structure-function properties of ACR4 and to delineate the downstream protein-protein interactions mediated by the kinase domain. Elucidation of the signal transduction pathways in seed development is expected to provide key insights into novel strategies to produce grain for food, feed and renewable fuels.
2. Tuberization in potato is influenced by length of daylight or photoperiod mediated via the light-receiving organ, the leaf, to an underground organ, the stolon. The laboratory of Dr. David Hannapel in the Dept. of Horticulture has identified a novel, mobile RNA in potato, designated StBEL5, which encodes a transcription factor that regulates tuber formation. This mRNA participates in a leaf to stolon signal pathway that involves long-distance transport regulated by photoperiod. The long-term goal of our collaborative program is to identify RNA-binding proteins that mediate the transport, regulate stability and/or control translation of StBEL5 RNA as it functions in this signaling pathway.

Research Funding

1. Gateways for photoperiod-mediated RNA trafficking (P.I., David Hannapel; Co-P.I., Guru Rao) USDA-NRI-CGP, $400,000 for the period 2008-2012.

2. Transferring research from a model system to uncover the network that regulates long-distance signaling in potato (P.I., David Hannapel (ISU) ; Co-P.I’s: Guru Rao (ISU); William J. Lucas (U.C. Davis); Jeffery Coller (CWRU). NSF, Plant Genome Research Program. $2.76M for the period 2008-2012.

3. A comprehensive application of phage display for high throughput screening and affinity selection of protein/peptide ligands (P.I. Guru Rao). Funding from Archer Daniels Midland (ADM), $489,469 for the period 1/1/2011 through 12/31/2013.

Selected Publications

1: Shah S, Butler NM, Hannapel DJ, Rao AG. Mapping and characterization of the
interaction interface between two polypyrimidine-tract binding proteins and a
nova-type protein of Solanum tuberosum. PLoS One. 2013 May 24;8(5):e64783. doi:
10.1371/journal.pone.0064783. Print 2013. PubMed PMID: 23717658; PubMed Central
PMCID: PMC3663837.

2: Singh AP, Das RN, Rao G, Aggarwal A, Diegelmann S, Evers JF, Karandikar H,
Landgraf M, Rodrigues V, Vijayraghavan K. Sensory neuron-derived eph regulates
glomerular arbors and modulatory function of a central serotonergic neuron. PLoS
Genet. 2013 Apr;9(4):e1003452. doi: 10.1371/journal.pgen.1003452. Epub 2013 Apr
18. PubMed PMID: 23637622; PubMed Central PMCID: PMC3630106.

3: Srivastava R, Deng Y, Shah S, Rao AG, Howell SH. BINDING PROTEIN is a master
regulator of the endoplasmic reticulum stress sensor/transducer bZIP28 in
Arabidopsis. Plant Cell. 2013 Apr;25(4):1416-29. doi: 10.1105/tpc.113.110684.
Epub 2013 Apr 26. PubMed PMID: 23624714; PubMed Central PMCID: PMC3663277.

4: Jacobs C, Coss Adame E, Attaluri A, Valestin J, Rao SS. Dysmotility and proton
pump inhibitor use are independent risk factors for small intestinal bacterial
and/or fungal overgrowth. Aliment Pharmacol Ther. 2013 Jun;37(11):1103-11. doi:
10.1111/apt.12304. Epub 2013 Apr 10. PubMed PMID: 23574267.

5: Matsui JT, Vaidya JG, Johnson HJ, Magnotta VA, Long JD, Mills JA, Lowe MJ,
Sakaie KE, Rao SM, Smith MM, Paulsen JS. Diffusion weighted imaging of prefrontal
cortex in prodromal huntington’s disease. Hum Brain Mapp. 2013 Apr 9. doi:
10.1002/hbm.22273. [Epub ahead of print] PubMed PMID: 23568433.

6: Meyer MR, Shah S, Rao AG. Insights into molecular interactions between the
juxtamembrane and kinase subdomains of the Arabidopsis Crinkly-4 receptor-like
kinase. Arch Biochem Biophys. 2013 Jul 15;535(2):101-10. doi:
10.1016/ Epub 2013 Apr 6. PubMed PMID: 23567842.

7: Singh S, Heady S, Coss-Adame E, Rao SS. Clinical utility of colonic manometry
in slow transit constipation. Neurogastroenterol Motil. 2013 Jun;25(6):487-95.
doi: 10.1111/nmo.12092. Epub 2013 Feb 6. PubMed PMID: 23384415.

8: Schey R, Cromwell J, Rao SS. Medical and surgical management of pelvic floor
disorders affecting defecation. Am J Gastroenterol. 2012 Nov;107(11):1624-33;
quiz p.1634. doi: 10.1038/ajg.2012.247. Epub 2012 Aug 21. Review. PubMed PMID:

9: Smith MM, Mills JA, Epping EA, Westervelt HJ, Paulsen JS; PREDICT-HD
Investigators of the Huntington Study Group. Depressive symptom severity is
related to poorer cognitive performance in prodromal Huntington disease.
Neuropsychology. 2012 Sep;26(5):664-9. doi: 10.1037/a0029218. Epub 2012 Jul 30.
PubMed PMID: 22846033.

10: Cruz L, Rao JS, Teplow DB, Urbanc B. Dynamics of metastable β-hairpin
structures in the folding nucleus of amyloid β-protein. J Phys Chem B. 2012 Jun
7;116(22):6311-25. doi: 10.1021/jp301619v. Epub 2012 May 24. PubMed PMID:
22587454; PubMed Central PMCID: PMC3394227.

11: Nasr I, Attaluri A, Coss-Adame E, Rao SS. Diagnostic utility of the
oesophageal balloon distension test in the evaluation of oesophageal chest pain.
Aliment Pharmacol Ther. 2012 Jun;35(12):1474-81. doi:
10.1111/j.1365-2036.2012.05103.x. Epub 2012 Apr 23. PubMed PMID: 22524415.

12: Harrington DL, Smith MM, Zhang Y, Carlozzi NE, Paulsen JS; PREDICT-HD
Investigators of the Huntington Study Group. Cognitive domains that predict time
to diagnosis in prodromal Huntington disease. J Neurol Neurosurg Psychiatry. 2012
Jun;83(6):612-9. doi: 10.1136/jnnp-2011-301732. Epub 2012 Mar 26. PubMed PMID:

13: Long JD, Matson WR, Juhl AR, Leavitt BR, Paulsen JS; PREDICT-HD Investigators
and Coordinators of the Huntington Study Group. 8OHdG as a marker for Huntington
disease progression. Neurobiol Dis. 2012 Jun;46(3):625-34. doi:
10.1016/j.nbd.2012.02.012. Epub 2012 Mar 5. PubMed PMID: 22414782.

14: Feiss M, Rao VB. The bacteriophage DNA packaging machine. Adv Exp Med Biol.
2012;726:489-509. doi: 10.1007/978-1-4614-0980-9_22. Review. PubMed PMID:

15: Cheeney G, Nguyen M, Valestin J, Rao SS. Topographic and manometric
characterization of the recto-anal inhibitory reflex. Neurogastroenterol Motil.
2012 Mar;24(3):e147-54. doi: 10.1111/j.1365-2982.2011.01857.x. Epub 2012 Jan 11.
PubMed PMID: 22235880.

16: Remes-Troche JM, Attaluri A, Chahal P, Rao SS. Barostat or dynamic balloon
distention test: which technique is best suited for esophageal sensory testing?
Dis Esophagus. 2012 Sep-Oct;25(7):584-9. doi: 10.1111/j.1442-2050.2011.01294.x.
Epub 2011 Dec 13. PubMed PMID: 22168228.

17: Schey R, Rao SS. The role of rifaximin therapy in patients with irritable
bowel syndrome without constipation. Expert Rev Gastroenterol Hepatol. 2011
Aug;5(4):461-4. doi: 10.1586/egh.11.50. Review. PubMed PMID: 21780893.

18: Schey R, Rao SS. Lubiprostone for the treatment of adults with constipation
and irritable bowel syndrome. Dig Dis Sci. 2011 Jun;56(6):1619-25. doi:
10.1007/s10620-011-1702-2. Epub 2011 Apr 27. Review. PubMed PMID: 21523369.

19: Wilken J, Rao S, Estin M, Saltzman CL, Yack HJ. A new device for assessing
ankle dorsiflexion motion: reliability and validity. J Orthop Sports Phys Ther.
2011 Apr;41(4):274-80. doi: 10.2519/jospt.2011.3397. Epub 2011 Apr 1. PubMed
PMID: 21460462.

20: Rao SS. Biofeedback therapy for constipation in adults. Best Pract Res Clin
Gastroenterol. 2011 Feb;25(1):159-66. doi: 10.1016/j.bpg.2011.01.004. Review.
PubMed PMID: 21382587; PubMed Central PMCID: PMC3073852.

Invited Talks

2007 Engineering proteins for nutritional value. International meeting of the Crop Science
Society of America, New Orleans, November 4-8.
2005 Improving the Plant Secretory System for Nutrition and Health. Mini-symposium
organized by the Rank Prize Funds, Grasmere, U.K., May 23-26.


2010 Provisional patent application “Peptide Domains that Bind Small Molecules of Industrial Significance”

2009 Isolated polynucleotide molecules corresponding to mutant and wild-type alleles of the maize D9 gene and methods of use (patent # 7,557,266)
2007 Expression cassettes for producing plants with increased levels of essential amino acids (patent # 7,211,431 B2)
2007 Altering protein functional properties through terminal fusions (patent # 7,160,988)
2007 Method for integration of foreign DNA into eukaryotic genomes (patent # 7223601)
2006 Alteration of amino acid composition in seeds (patent # 7053282)
2005 Composition and methods for altering amino acid content of proteins (patent # 6905877)
2004 Novel high lysine proteins (patent # 6,800,726)
2001 Amino polyol amine oxidase and related polypeptides and methods of use (patent # 6211434).
2001 Method for integration of foreign DNA into eukaryotic genome (patent # 6262341)
2000 Peptide derivatives of tachyplesin having antimicrobial activity (patent # 6015941).
1999 Derivatives of Bauhinia purpurea lectin and their use as larvicides (patent # 5945589)
1999 High lysine derivatives of -hordothionin (patent # 5990389)
1999 High threonine derivatives of -hordothionin (patent # 5885801)
1999 High methionine derivatives of -hordothionin(patent # 5885802)
1998 Commercial production of aprotinin in plants (patent # 5824870)
1997 Methionine derivatives of hordothionin for pathogen control (patent # 5703049)
1997 Synthetic antimicrobial peptides (patent # 5607914 and 5717061)
1996 Peptide derives. of Tachyplesin having inhibitory activity towards plant pathogenic fungi (patent # 5580852)
1996 Peptide with inhibitory activity towards plant pathogenic fungi (patent # 5488035)
1995 Synthetic antifungal peptides (patent # 5464944)
1995 Larvicidal Lectins and Plant Insect Resistance Based Thereon (patent # 5407454)