California State University at Los Angeles
Dept. of Chemistry and Biochemistry
5151 University Drive
Los Angeles, CA 90032
Tel: (323) 343-2361
Fax: (323) 343-6490
1983 Bachelor of Science, Biochemistry, UCLA, Los Angeles, CA
1989 Doctor of Philosophy, Biochemistry, UCLA, Los Angeles, CA
1992 Postdoctoral Fellow, Molecular Biology, Princeton Univ., Princeton, NJ
2007-present Professor, Department of Chemistry and Biochemistry, CSULA, Los Angeles, CA.
2012-present Advisor, Bioinformatics and Computational Biology Minor
2015-present MS-to-PhD RISE Coordinator, Minority Opportunities in Research (MORE) Program
2003-2007, Graduate Student Advisor, Department of Chemistry and Biochemistry, CSULA
2006-2011 Director, CSULA-City of Hope Cancer Collaborative
2002-2009 Director, Southern California Bioinformatics Summer Institute
2003-2007 Associate Professor, Department of Chemistry and Biochemistry, CSULA, Los Angeles, CA.
1999-2003 Assistant Professor, Department of Chemistry and Biochemistry, CSULA, Los Angeles, CA.
1992-1999 Assistant Scientist, Department of Cell and Tumor Biology, Beckman Research Institute, City of Hope, Duarte, CA.
HONORS AND AWARDS
1994-96 Edward Livingston Trudeau Scholar, American Lung Assoc.
1999 Cornelius L. Hopper Scientific Achievement Award (Honorable Mention)
2000 Invited Speaker, “Tumor suppressor genes and oncogenes in breast cancer”, Sept.
20, City of Hope National Medical Center, Duarte, CA.
2001 Invited Speaker, “Cancer Genetics”, Feb. 19, City of Hope National Medical Center, Duarte, CA
2001 Invited speaker, “Redox Regulation of Transcription Factors”, Feb. 9, UCLA, Los Angeles, CA
2001 Invited speaker, “Bioinformatics at CSULA”, Nov. 3, Valley College, Los Angeles, CA
2002 Invited speaker, “CSULA Bioinformatics Program”, Jan. 11, CSUPERB Conference Bioinformatics Interest Group, Cal Poly Pomona University, Pomona, CA
2002 Invited speaker, “Somatic Cancer Genetics”, Mar. 18, City of Hope National Medical Center, Duarte, CA
2002 Invited speaker, “Structural Bioinformatics”, Oct. 21, 2002, Pasadena City College, Pasadena, CA.
2002 Invited speaker, “Bioinformatics”, Valley College, Los Angeles, CA
2003 Invited speaker, “Mechanisms of Carcinogenesis and Mutagenesis”, City of Hope National Medical Center, Duarte, CA
2003 Invited speaker, “Redox Regulation of Transcription Factors,” Beckman Research Institute at City of Hope Lake Arrowhead, CA
2004 Invited speaker, “New Thoughts on an Old Problem: How is p53 Regulated?”, City of Hope National Medical Center, Duarte, CA
2004 Invited speaker, “p53: Master Responder to Cellular Stress”, Cal State Long Beach, Long Beach, CA
2005 Invited speaker, “Redox Regulation of the p53 Tumor Suppressor Gene”, UC Riverside, Riverside, CA
2010 Invited speaker, “Using computers to predict protein oxidation”, Dept. of Chemistry and Biochemistry, Cal State Long Beach, Long Beach, CA.
2010 Visiting Professor, Institute for Advanced Studies, Princeton, NJ.
2011 Invited speaker, “Evolution of the MDM2 family genes”, Southern California Systems Biology Conference, UC Irvine, Irvine, CA.
2012, 13 Invited speaker, “Cancer 101: from the basics to the latest”, Cancer Research and Awareness Society, Cal State LA University, Los Angeles, CA.
2014 Invited speaker, "Cancer Biology: How cells become cancerous and evade chemotherapy.", Harvey Mudd College, Claremont, CA.
2015 Outstanding Professor of the Year, CSULA
2016 Invited speaker, “Skills for a career in bioinformatics and genomics”, GCAT-SEEK Workshop, Cal State LA University, Los Angeles, CA.
MEMBERSHIP IN PROFESSIONAL SOCIETIES
American Association for the Advancement of Science
American Association for Cancer Research
Advisory Board of the Economic Development Network of California Community Colleges
Member, Faculty Consensus Group, Calif. State Univ. Program for Research and Biotechnology (’16-present).
Member, 23andMe Education Advisory Board (’16-present)
Chair, CSULA Chemistry Dept, Personnel Committee B (’05-’06; ’13-present)
University Fiscal Policy Committee (’16-present)
Member and Cofounder, CSULA Bioinformatics Consortium (00’-‘06)
University Academic Senator (’09-’12)
Chair, CSULA Chemistry Dept, Information Resource Committee (03’-04’)
Chair, CSULA Radiation Safety Committee (01’-04’)
Chair, CSULA Chemistry Dept, Instructional Affairs Committee ’11-‘12)
Chair, CSULA Chemistry Dept, Graduate Studies Committee (’08-’09)
Chair, CSULA Chemistry Dept, Faculty Search Committee (’13-‘14)
Honors College/Liberal Studies joint Faculty Search Committee (’13-‘14)
Visioning Task Force ('13-'15)
University Education Policy Committee (’06-’07, ’12-‘14)
NSS College Committee A ('14-‘15)
CSULA Chemistry Dept, Instructional Affairs Committee (’05-’07, ’11-'14)
CSULA Chemistry Dept, Fiscal Affairs Committee (’06-‘07)
CSULA Radiation Safety Committee (‘06-‘12)
Search Committee, University Librarian (’05)
National Institutes of Health
Small Business Innovation Research Program (Molecular Genetics/Cell Biology)-Ad hoc Study Section Member (1996-97)
Cancer Health Disparities Study Section Member (2007, 2009)
National Science Foundation
Graduate Fellowship Study Section Member (Structural Biology) (2005)
Graduate Fellowship Study Section Chair (Structural Biology) (2006)
Ad hoc reviewer for:
Biochim Biophys Acta
British Journal of Cancer
Expert Opin. Ther. Patents
Free Radicals in Medicine
International Journal of Cancer
J. Inorganic Chem
J. Clin. Investigation
J. Laboratory Investigation
Nature Chemical Biology
Cell Biology International
Medicinal Chemistry Communications
Associate Editor for Gene (2017-present)
Judge, Annual New Horizon Middle School Science Fair, Pasadena, CA, 1999-2013
Judge, 3rd Annual National Science Foundation Alliance for Minority Participation Research Conference, Irvine, CA, July 31, 1995
Judge, Annual California State Science Fair, California Science Center, Los Angeles, CA, May 1999-2000, 2006, 2012.
Faculty sponsor and co-founder, Cancer Research and Awareness Society, Cal State LA ASI student group. (2012-present)
Annual speaker at the Los Angeles Job Corps Center for the No-smoking campaign. Title of presentation: “If You Smoke Or Vape, Quit. If You Don’t Smoke Or Vape, Don’t Start”
Momand, J. 2011, 'Cuts undermine our universities - and our workforce', Daily Breeze, 15 October.
Momand, J. 2006, 'What would Muhammad do?', Los Angeles Times, 9 February.
Selected Journal Publications (total of 35 publications; number of citations >9000)
Momand, J. and Clarke, S. (1987). Rapid degradation of D- and L-succinimide-containing peptides by a post proline endopeptidase from human erythrocytes. Biochemistry 26, 7798-7805.
Momand, J.A. and Clarke, S. (1990). The fidelity of protein synthesis: Can mischarging by aspartyl-tRNAAsp synthetase lead to the formation of isoaspartyl residues in proteins? Biochem. Biophys. Acta 1040, 153-158.
Levine, A.J. and Momand, J. (1990). Tumor suppressor genes: the p53 and retinoblastoma sensitivity genes and gene products. Biochem. Biophys. Acta 1032, 119-136.
Levine, A.J., Momand, J. and Finlay, C.A. (1991). The p53 tumor suppressor gene. Nature 351, 453-456.
Momand, J., Zambetti, G.P., Olson, D.C., George, D. and Levine, A.J. (1992). The mdm-2 oncogene product forms a complex with the p53 protein and inhibits p53 mediated transactivation. Cell 69, 1237-1245.
Seto, E., Usheva, A., Zambetti, G.P., Momand, J., Horikoshi, N., Weinman, R., Levine, A.J., and Shenk, T. (1992).Wild-type p53 binds to the TATA binding protein and interferes with transcription. Proc. Natl. Acad. Sci. USA 89, 12028-12032.
Olson, D.C., Marechal, V., Momand, J., Chen, J. Romacki, C., and Levine, A.J. (1993). Identification and characterization of multiple mdm-2 proteins and mdm-2-p53 protein complexes. Oncogene 8, 2353-2360.
Momand, J. and Zambetti, G.P. (1996). Analysis of the proportion of p53 bound to mdm-2 in cells with defined growth characteristics. Oncogene 12, 2279-2289.
Sepehrnia, B., Paz, I.B., Dasgupta, G. and Momand, J. (1996). Heat Shock Protein 84 forms a complex with mutant p53 protein predominantly within a cytoplasmic compartment of the cell. J. Biol. Chem. 271, 15084-15090.
Momand, J. and Sepehrnia, B. Detection and Isolation of Recombinant Proteins from Mammalian Cells by Immunoaffinity Chromatography: p53. In "Methods in Molecular Biology: Expression and Detection of Recombinant Genes," (R.S. Tuan, ed.), vol. 63, pp 161-172, 1997, Humana Press, Clifton, NJ.
Momand, J. and Zambetti, G.P. (1997). Mdm-2: "Big Brother" of p53. J. Cell. Biochem. 64, 343-352.
Chin, P.L., Momand, J. and Pfeifer, G.P. (1997). In vivo evidence for binding of p53 to consensus binding sites in the p21 and GADD45 genes in response to ionizing radiation. Oncogene 15, 87-99.
Botuyan, M.V., Momand, J., Chen, Y. (1997). Solution conformation of an essential region of the p53 transactivation domain. Folding & Design 2, 331-342.
Dasgupta, G. and Momand, J. (1997). Geldanamycin prevents nuclear translocation of mutant p53. Exp. Cell. Res. 237, 29-37.
Wu, H.-H. and Momand, J. (1998). Pyrrolidine dithiocarbamate prevents p53 activation and promotes p53 cysteine residue oxidation. J. Biol. Chem. 273, 18898-18905.
Momand, J., Jung, D. and Niland, J. (1998). The MDM2 gene amplification database. Nucleic Acids Res. 26, 3453-3459.
Li, J.R., Chou, C.K., McDougall, J., Dasgupta, G., Wu, H.-H., Ren, R.L., Lee, A. and Momand, J. (1999). p53 tumor suppressor protein in normal human fibroblasts does not respond to 837 MHz microwave exposure. Radiation Research 151, 710-716
Wu, H.-H., Sherman, M., Yuan, Y.-C., and Momand, J. (1999). Direct redox modulation of p53 protein: potential sources of redox control and potential outcomes. Gene Ther. Mol. Biol. 4, 119-132.
Momand, J., Wu, H.-H. and Dasgupta, G. (2000). MDM2-master regulator of the p53 tumor suppressor protein. Gene 242 15-29.
Coleman, A.B., Momand, J., and Kane, S.E. (2000). Basic fibroblast growth factor sensitizes NIH 3T3 cells to apoptosis induced by cisplatin. Mol. Pharm. 57:324-333.
Wu, H.-H., Thomas, J.A. and Momand, J. (2000). p53 protein oxidation in cultured cells in response to PDTC-a novel method for relating the amount of p53 oxidation in vivo to the regulation of p53-responsive genes. Biochem. J. 351:87-93.
Makmura, L., Areopagita, A., Furuta, S., Muñoz, A. and Momand, J. (2001). Development of a sensitive assay to detect reversibly oxidized cysteine sulfhydryl groups. Antioxid. Redox Signal. 3:1105-1118.
Furuta, S., Ortiz, F., Sun, X.Z., Wu, H-H, Mason, A., and Momand, J. (2002). Copper uptake is required for pyrrolidine dithiocarbamate-mediated oxidation and protein level increase of p53 in cells. Biochem. J. 365, 639-648.
Momand, J., Furuta, S., and Aspuria, P.J. (2004). “MDM2 and MDMX-regulators of p53 activity”, a chapter in The p53 Tumor Suppressor Pathway and Cancer, Kluwer Academic/Plenum Publishers (New York, NY).
Sun, X.Z., Nguyen, J., and Momand, J. (2003). Purification of recombinant p53 from Sf9 insect cells. p53 Protocols; Methods in Molecular Biology Series, Humana Press, 234 , 17-28.
Sun, X.Z., Vinci, C., Makmura, L., Han, S., Tran, D., Nguyen, J., Hamann, M., Grazziani, S., Sheppard, S., Gutova, M., Zhou, F., Thomas, J., and Momand, J. (2003). Formation of disulfide bond in p53 correlates with inhibition of DNA binding and tetramerization. Antioxid. Redox Signal. 5, 655-665.
Yao, X., Li, X., Toledo, F., Zurita-Lopez, C., Gutova, M., Momand, J., Zhou, F. (2006). Sub-attomole oligonucleotide and p53 cDNA determinations via a high-resolution SPR combined with oligonucleotide-capped gold nanoparticle signal amplification. Anal. Biochem. 354, 220-228.
Harrigan, J.A., Fan, J., Momand, J., Perrino, F.W., Bohr, V.A., Wilson, D.M.III (2006). WRN exonuclease activity is blocked by DNA termini harboring 3' obstructive groups. Mech of Ageing Dev, 128, 259-266.
Krilowicz, B., Sharp, S.B., Warter-Perez, N., Johnston, W., Momand, J. (2007). A summer program designed to educate college students for careers in bioinformatics. CBE-Life Sci. Educ. 6, 74-83.
Wang J., Zhu X., Tu Q., Guo Q., Zarui C.S., Momand J., Sun X.Z., and Zhou F. (2008). Capture of p53 by electrodes modified with consensus DNA duplexes and amplified voltammetric detection using ferrocene-capped gold nanoparticle/streptavidin conjugates. Anal Chem. 80, 769-774.
Sanchez, R., Riddle, M., Woo, J., and Momand, J. (2008). Prediction of reversibly oxidized protein cysteine thiols using protein structure properties. Protein Sci. 17, 473-481.
Momand J., Villegas A., and Belyi V.A. (2011). The evolution of MDM2 family genes. Gene 486, 23-30.
Warner, W.A., Sanchez, R., Dawoodian, A., Li, E., and Momand, J. (2012). Identification of FDA-approved drugs that computationally bind to MDM2. Chem. Biol. Drug Des. 80, 631-637.
Mendoza, M., Mandani, G., and Momand, J. (2014). The MDM2 gene family. Biomol. Concepts 5, 9-19 DOI 10.1515/bmc-2013-0027.
Warner, W.A., Wong, D.J., Palma-Diaz, F., Shibuya, T.Y., Momand, J. (2015). Clinicopathological and Targeted Exome Gene Features of a Patient with Metastatic Acinic Cell Carcinoma of the Parotid Gland Harboring an ARID2 Nonsense Mutation and CDKN2A/B Deletion. Case Rep Oncol Med. 2015:893694. PubMed PMID: 26634163; PubMed Central PMCID: PMC4655020.
Theile, D., Geng, S., Denny, E.C., Momand, J., Kane, S.E. (2017). t-Darpp stimulates protein kinase A activity by forming a complex with its RI regulatory subunit. Cell Signal. 40, 53-61. PubMed PMID: 28867659; PubMed Central PMCID: PMC5651189
Momand, J., Magdziarz, P., Feng, Y., Jiang, D., Parga, E., Celis, A., Denny, E., Wang, X., Phillips, M.L., Monterroso, E., Kane, S.E., Zhou, F. (2017). t-Darpp is an elongated monomer that binds to calcium and is phosphorylated by cyclin-dependent kinases 1 and 5. FEBS Open Bio. 7, 1328-1337. PubMed PMID: 28904862; Pubmed Central PMCID: PMC5586343
Lenz, G., Hamilton, A., Geng, S., Hong, T., Kalkum, M., Momand, J., Kane, S., Huss, J. (2017). t-Darpp activates IGF-1R signaling to regulate glucose metabolism in trastuzumab-resistant breast cancer cells. Clin Cancer Res. pii: clincanres.0824.2017. doi: 10.1158/1078-0432.CCR-17-0824. [Epub ahead of print] PubMed PMID: 29180608.
Momand, J. and McCurdy, A. Concepts in Bioinformatics and Genomics; Oxford University Press: New York, 2017.
1RO1GM105898 09/01/14 – 07/31/18
Macromolecular Interactions of t-Darpp and Darpp-32
Direct + indirect = $1.25 Million
Role: PI (note, this is a shared PI grant with Drs Susan Kane and Feimeng Zhou)
1K12GM106996 06/01/16 – 05/31/21
Institutional Research and Academic Career Development Award
PI: Michael Carey, UCLA
My role on the grant is to train UCLA post-doctoral fellows in instruction of biochemistry using new pedagogy.
Pending Research Support
EXPERIENCE OF PI
Thesis Advisor and Postgraduate-Scholar Sponsor:
Thesis Advisor: Hsiao-Huei Wu, Ph.D. 1999, now a Research Professor at the University of Southern California.
Thesis Advisor: Saori Furuta, M.S. 2001, Ph.D. program UC Irvine (awarded 2007)
Thesis Advisor: John Ngyuen, M.S. 2002 Baxter Corp.
Thesis Advisor: Paul-Joseph Aspuria, Ph.D. program UCLA (awarded 2011)
Thesis Advisor: Christopher Vinci, Ph.D. program UCLA (awarded 2011)
Thesis Advisor: George Abuelkhair, M.S., 2004
Thesis Advisor: Margarita Gutova, M.S., 2004, City of Hope Natl. Medical Center Technician
Thesis Advisor: Lemar Smith, Ph.D. program UC Riverside (2005-present),
Thesis Advisor: Jake Leon, M.S., 2006, Grifols Inc.
Thesis Advisor: Giau Hua, M.S., 2007, City of Hope National Medical Center Technician
Thesis Advisor: Grace Idana Masangkay, M.S., 2007, Ph.D. program UCLA (awarded 2013)
Thesis Advisor: Shefali Prabhaker, M.S. 2007, Repligen Corp
Thesis Advisor: Deborah Jarret, M.S. 2008, Ph.D. program, UCLA
Thesis Advisor: Cari Wilson, M.S. 2010
Thesis Advisor: En-Renn Yeh, M.S. 2011 Biotech company in Taiwan.
Thesis Advisor: James O’Hearn, Ph.D. program, UCLA
Thesis Advisor: Pauline Lenechik, M.S. 2011, Quantimetrix company
Thesis Advisor: Mecca Madany, M.S. 2012, Ph.D. program Cedar Sinai Hospital
Thesis Advisor: Ronak Derakhshandeh, M.S. 2012, Staff Research Associate at UCSF
Thesis Advisor: Ricardo Sanchez, M.S. 2012, Thermo-Fisher-Instruments division
Thesis Advisor: Arianna Celis, M.S. 2013, Ph.D program, Univ. of Montana
Thesis Advisor: Kevin Zhou, M.S. 2013, Phenomenex company
Thesis Advisor: Mario Gallardo, M.S. 2014, Grifols Inc.
Thesis Advisor: Elizabeth Parga, M.S. 2015, Research Assoc. at City of Hope
Thesis Advisor: Chris Quan, M.S. 2015, industry
Thesis Advisor: Patrycja Magdziarz, M.S. 2015, Research Assistant at CSULA
Thesis Advisor: Garni Mandaani, M.S. 2016, Grifols Inc.
Thesis Advisor: Jonathan Castillo, M.S. 2016, Ph.D. program, USC.
Thesis Advisor: Aracely Acevedo, M.S. 2016, Ph.D. program, UCLA.
Thesis Advisor: Edgar Perez, M.S. 2017, Research assistant at UCLA.
Thesis Advisor: Clara Cano, M.S. 2017, Instructor, CSULA.
Postgraduate Sponsor Advisor: Dr. Xiu Zhu Sun. (retired)
Student Research Assistants:
The following undergraduate students have conducted research under my auspices since 1999: Amparo Munoz, Eddie Lares (Stanford Medical School, started 2002), Kandace West, Fausto Ortiz, Linna Makmura (now a research technician at the House Eye, Ear, Nose and Throat Institute in Los Angeles), Daniel Honono, David Arce, Maricela Castaneda, Giau Hua (now a research technician at City of Hope), Cecilia Zurita (now a tenure-track professor), Joyce Ho (now in MS program in Biology at CSULA), Ai Yuasa, Mark Rivera (now in the UC Berkeley Ph. D. Program), Roubina Tavosian, Jessica Ponce (now in the University of Iowa Ph.D. program), Esther Li, Alex Dawoodian (now in Podiatry School at Western University), Tiffany Kilbas (just graduated), Alberto Villegas (just graduated), Adrian Berliner (now in Ph.D. program at Harvard), Wayne Warner (now in Ph.D. program at Washington U.), Fernando Vargas (now in Ph.D. program in UC San Diego), Manasvi Pinnamanemi (applying to med. school), Sara Arenas (post-baccalaureate program, Wake Forest University), Robyn Latimer (current), Jesus Aldana (current), Phillip Farias (current), Donna Mendoza (current), Catherine Clarke (current), Sarwyn Singh (current).
PRIOR EXTRAMURAL GRANTS AWARDED (in chronological order)
American Lung Association Research Grant (7/1/94-6/30/96)
Title: Identification of a novel p53 binding protein.
Total direct: $50,000
Total indirect: none
Role on project: PI
Young Investigator Award, UC Breast Cancer Research Program (7/1/95-6/30/98)
Title: Alternate mechanisms of p53 inactivation in breast cancer.
Total direct: $211,153
Total indirect: $115,478
Role on project: PI
American Cancer Society-California Division (7/1/98-6/30/99)
Oncology Grant Project for Health Professional Student (for H.-H. Wu)
Title: Redox regulation of the p53 tumor suppressor protein.
Total direct: $1,500
Total indirect: none
Role on project: PI
Title: COH Clinical Oncology Research Development Program
Role on project: Mentor, 2.5% effort, no compensation
PI: James Doroshaw, MD
The following grants were awarded while employed at Cal State LA University
NIGMS SCORE Program Project (7/1/00-6/30/04)
Title of Subproject: Redox Regulation of Transcription Factors
Role on Subproject: P.I.
Program Director: Carlos Gutierrez
NIH/NCI Academic Research Enhancement Award (8/15/03-8/14/06)
Title: Response of p53 Promoter to Hydrogen Peroxide
NSF Major Research Instrumentation Program (07/01/04 - 06/30/05)
Title: Acquisition of a Proteome Analyzer
NIGMS SCORE Program Project-Equipment Supplement (7/1/00-6/30/03)
Title: Score: Research Excellence at Cal State LA
Role on Subproject: PI
Program Director: Carlos G. Gutierrez
Dept. of Defense (10/1/02-9/30/04)
Title: Instrumentation for Research and the Undergraduate Curriculum
Role on Subproject: co-PI
PI: Frank Gomez
NIH-NSF EEC-0609454 (10/1/02-9/30/09)
NIH-NSF Bioinformatics Bioengineering Summer Institute Program
Southern California Bioinformatics Summer Institute
This is a grant that funds undergraduate and graduate students to train in bioinformatics at CSULA and perform research at universities, research institutes, and companies in the Southern California area.
Role: PI and Program Director
Title: CSULA-COH Collaborative to Study Cancer Disparities
Response to program announcement number RFA-CA-06-013. This is research and training collaborative program between California State University Los Angeles and the City of Hope. The goals are to increase the participation and capacity of minority students and minority faculty in cancer research, especially as it relates to cancer disparities among minority populations; and 2) to increase our understanding, at the molecular, behavioral, and psychosocial levels, of cancer disparities among minority populations.
Role: PI and Program Director
Koshland Foundation (01/05/09-12/31/10)
Title: Kabul University Faculty Training Program in Biochemistry at CSULA
Role: Program Director
5T36GM078013 Henderson, J. (PI) (07/05/08 – 06/30/13)
Title: Improving Quantitative Skills of Life Science Majors at Cal State Los Angeles
In this project it is prosposed that an interdisciplinary Center for Quantitative Analysis be created. That there be curriculum changes for life science majors to make them more quantitative. Develop a new Bioinformatics and Computational Biology Minor program.
Direct: $1.1 million
Role: Senior Personnel
INTRAMURAL GRANTS AWARDED
Center for Effective Teaching and Learning (Sept. 1, 2000-June 30, 2001)
Title: Development of Curricula for Education in Bioinformatics
Role on Subproject: P.I.
Center for Effective Teaching and Learning (Sept. 1, 2002-June 30, 2003)
Title: Development of Introductory Bioinformatics Course
Role on Subproject: P.I.