Elaine M. Tobin

Elaine Munsey was born in Louisville, Kentucky on December 23, 1944. Her family had immigrated from Odessa and Lithuania. Munsey's interests included science, mathematics and basketball. She attended the 1960 Democratic National Convention as a volunteer working for Adlai Stevenson II's presidential campaign. While in high school, she also participated in civil rights marches and heard Martin Luther King Jr. speak in Louisville.

She graduated from Seneca High School in Louisville in 1962.{{cite web |title=Hall of Fame |url=https://www.senecaforever.org/alumni/hall-of-fame/ |website=Seneca Forever |access-date=23 May 2022}}

She earned her Bachelor of Arts degree from Oberlin College in 1966, majoring in chemistry. After graduation, she spent a summer as an Appalachian Volunteer, working as a community organizer in Wolfe County, Kentucky, as part of Lyndon Johnson's War on Poverty.

She was accepted into the Biology Department at Stanford. She took classes in plant physiology with Winslow Briggs, worked in his laboratory, and transferred to Harvard when Briggs took a professorship there. In 1968 she married Allan J. Tobin. They spent a year at the Weizmann Institute of Science in Israel, where Elaine Tobin worked with plant geneticist Ezra Galun. After returning to North America, she completed her Ph.D. in Biology at Harvard University in 1972. She later married J. Philip Thornber.{{cite book |last1=Thornber |first1=J. Philip |chapter=Thirty Years of Fun with Antenna Pigment-Proteins and Photochemical Reaction Centers: A Tribute to the People Who Have Influenced My Career |title=Discoveries in Plant Biology |date=2000 |volume=3 |pages=325–346 |doi=10.1142/9789812813503_0017 |publisher=World Scientific|isbn=978-981-02-3882-7 }}

In 1973 Tobin went to Brandeis University, where she did postdoctoral work with Attila Klein, on the influence of light on the development of plants.

In 1975 she was hired in the Biology Department at University of California, Los Angeles (UCLA). Support was sparse, but she was able to get funding for basic research on plants from the National Institutes of Health (NIH). She was able to obtain laboratory space previously used by retiring professor Karl Hamner.{{cite journal |last1=Tobin |first1=Elaine |title=A Winding Road to a Happy Academic Career |journal=ASPB News |date=2008 |volume=35 |issue=6 |pages=11, 14 |url=https://aspb.org/newsletter/archive/2008/novdec08.pdf#page=11 |access-date=25 May 2022}}

As a student with Winslow Briggs, Tobin had been introduced to the effects of phytochrome on flowering and to the work of Karl Hamner on circadian rhythms and flowering.

Circadian rhythms in plants help them to coordinate with external light/dark cycles. Anticipating dawn, dusk, and seasonal day length allows plants to more effectively regulate both daily and seasonal activities, including the movement of leaves and petals, the opening of stomata for photosynthesis, stem growth, and the development of flowers.{{cite journal |last1=Daniel |first1=Xavier |last2=Sugano |first2=Shoji |last3=Tobin |first3=Elaine M. |title=CK2 phosphorylation of CCA1 is necessary for its circadian oscillator function in Arabidopsis |journal=Proceedings of the National Academy of Sciences of the United States of America |date=2 March 2004 |volume=101 |issue=9 |pages=3292–3297 |doi=10.1073/pnas.0400163101 |pmid=14978263 |pmc=365783 |issn=0027-8424|doi-access=free |bibcode=2004PNAS..101.3292D }}

Tobin first used Lemna gibba (duckweed) and later Arabidopsis thaliana (cress) as model plant systems to study light regulation of gene expression in plants, examining interactions between phytochrome photoreceptors, genes, and circadian rhythms.

Tobin was able to isolate poly(A) RNA from duckweed, expose slab gels to x-ray film, and show that while some mRNAs decreased in light, others increased.

In 1984, postdoctoral student Jane Silverthorne and Tobin demonstrated that photoreceptors in plants could affect the transcription of specific genes. Light-harvesting chlorophyll a/b-binding (LHCB) protein sequences from Lemna gibba were low in darkness but could be rapidly and reversibly restored by light exposure.{{cite book |last1=Sage |first1=Linda C. |title=Pigment of the Imagination: A History of Phytochrome Research|chapter=32. Gene regulation |date=2 December 2012 |publisher=Elsevier |isbn=978-0-323-13854-3 |pages=480–515 |chapter-url=https://books.google.com/books?id=fUhihgURCjsC&pg=PA480 |access-date=23 May 2022 |language=en}}

Tobin's group also demonstrated phytochrome regulation of LHCB proteins (also known as cab genes) in Arabidopsis.{{cite journal |last1=Yakir |first1=Esther |last2=Hilman |first2=Dror |last3=Hassidim |first3=Miriam |last4=Green |first4=Rachel M. |title=Circadian Clock Associated1 Transcript Stability and the Entrainment of the Circadian Clock in Arabidopsis |journal=Plant Physiology |date=5 November 2007 |volume=145 |issue=3 |pages=925–932 |doi=10.1104/pp.107.103812 |pmid=17873091 |pmc=2048808 }}{{cite journal |last1=Tobin |first1=Elaine M. |title=My Path from Chemistry to Phytochrome and Circadian Rhythms |journal=Frontiers in Plant Science |date=2016 |volume=7 |page=261 |doi=10.3389/fpls.2016.00261 |pmid=27014288 |pmc=4791383 |issn=1664-462X|doi-access=free }}

By growing duckweed heterotrophically in the dark, and exposing it briefly to red and far-red light, Tobin demonstrated the effects of phytochromes on plant growth and transcription in rcbs genes.{{cite book |last1=Fosket |first1=Donald E. |title=Plant Growth and Development: A Molecular Approach |date=2 December 2012 |publisher=Elsevier |isbn=978-0-12-407792-8 |url=https://books.google.com/books?id=JIHNCgAAQBAJ&pg=PA297 |access-date=26 May 2022 |language=en}}

In a series of experiments beginning in 1993, Tobin's lab described DNA-binding activity with an affinity for LHCB in plant cells. Using a DNA fragment, they screened the Arabidopsis expression library, and cloned a protein with relevant binding activity, which they named CCA1. They showed that Circadian Clock Associated 1 (CCA1) was necessary for phytochrome response in Arabidopsis thaliana.{{cite journal |last1=Salomé |first1=Patrice A. |last2=McClung |first2=C. Robertson |title=The Arabidopsis thaliana Clock |journal=Journal of Biological Rhythms |date=October 2004 |volume=19 |issue=5 |pages=425–435 |doi=10.1177/0748730404268112 |pmid=15534322 |s2cid=19023414 |url=https://journals.sagepub.com/doi/pdf/10.1177/0748730404268112 |access-date=23 May 2022 |language=en |issn=0748-7304}}

Reports on the activity of CCA1 and a closely related gene (LHY) from George Coupland were submitted together to Cell in 1998. The two genes were the first two components of the circadian clock or central oscillator mechanism in plants to be identified.{{cite journal |last1=Nohales |first1=Maria A |last2=Kay |first2=Steve A |title=Molecular mechanisms at the core of the plant circadian oscillator |journal=Nature Structural & Molecular Biology |date=December 2016 |volume=23 |issue=12 |pages=1061–1069 |doi=10.1038/nsmb.3327 |pmid=27922614 |pmc=7750160 }}{{cite journal |last1=McClung |first1=CR |title=The Plant Circadian Oscillator. |journal=Biology |date=12 March 2019 |volume=8 |issue=1 |page=14 |doi=10.3390/biology8010014 |pmid=30870980 |pmc=6466001 |doi-access=free }} Among many other studies of the regulation and function of CCA1, Tobin has determined that one method of clock regulation involves the phosphorylation of CCA1 by the protein kinase CK2.{{cite journal |last1=Krahmer |first1=Johanna |last2=Hindle |first2=Matthew |last3=Perby |first3=Laura K. |last4=Mogensen |first4=Helle K. |last5=Nielsen |first5=Tom H. |last6=Halliday |first6=Karen J. |last7=Ooijen |first7=Gerben van |last8=Bihan |first8=Thierry Le |last9=Millar |first9=Andrew J. |title=The Circadian Clock Gene Circuit Controls Protein and Phosphoprotein Rhythms in Arabidopsis thaliana |journal=Molecular & Cellular Proteomics |date=1 January 2022 |volume=21 |issue=1 |page=100172 |doi=10.1016/j.mcpro.2021.100172 |pmid=34740825 |pmc=8733343 |url=https://www.mcponline.org/article/S1535-9476(21)00144-4/fulltext |access-date=24 May 2022 |language=English |issn=1535-9476}}

Elaine M. Tobin retired from teaching in 2014.{{cite journal |last1=Tobin |first1=Elaine |title=Adventures in Life and Science, from Light to Rhythms |journal=Annual Review of Plant Biology |date=20 May 2022 |volume=73 |issue=1 |pages=1–16 |doi=10.1146/annurev-arplant-090921-091346 |pmid=35130444 |s2cid=246650996 |issn=1543-5008}}

• {{cite journal |last1=Tobin |first1=Elaine M. |last2=Klein |first2=Attila O. |title=Isolation and Translation of Plant Messenger RNA |journal=Plant Physiology |date=1 July 1975 |volume=56 |issue=1 |pages=88–92 |doi=10.1104/pp.56.1.88 |pmid=16659264 |pmc=541303 }}
• {{cite journal |last1=Silverthorne |first1=Jane |last2=Tobin |first2=Elaine M. |title=Demonstration of transcriptional regulation of specific genes by phytochrome action |journal=Proceedings of the National Academy of Sciences |date=February 1984 |volume=81 |issue=4 |pages=1112–1116 |doi=10.1073/pnas.81.4.1112 |pmid=16593420 |pmc=344775 |language=en |issn=0027-8424|doi-access=free |bibcode=1984PNAS...81.1112S }}
• {{cite journal |last1=Tobin |first1=E M |last2=Silverthorne |first2=J |title=Light Regulation of Gene Expression in Higher Plants |journal=Annual Review of Plant Physiology |date=1 June 1985 |volume=36 |issue=1 |pages=569–593 |doi=10.1146/annurev.pp.36.060185.003033 |issn=0066-4294}}
• {{cite journal |last1=Karlin-Neumann |first1=George A. |last2=Sun |first2=Lin |last3=Tobin |first3=Elaine M. |title=Expression of Light-Harvesting Chlorophyll a/b -Protein Genes Is Phytochrome-Regulated in Etiolated Arabidopsis thaliana Seedlings |journal=Plant Physiology |date=1 December 1988 |volume=88 |issue=4 |pages=1323–1331 |doi=10.1104/pp.88.4.1323 |pmid=16666462 |pmc=1055760 }}
• {{cite journal |last1=Wang |first1=Z Y |last2=Kenigsbuch |first2=D |last3=Sun |first3=L |last4=Harel |first4=E |last5=Ong |first5=M S |last6=Tobin |first6=E M |title=A Myb-related transcription factor is involved in the phytochrome regulation of an Arabidopsis Lhcb gene. |journal=The Plant Cell |date=April 1997 |volume=9 |issue=4 |pages=491–507 |doi=10.1105/tpc.9.4.491 |pmid=9144958 |pmc=156934 }}
• {{cite journal |last1=Wang |first1=Zhi-Yong |last2=Tobin |first2=Elaine M |title=Constitutive Expression of the CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) Gene Disrupts Circadian Rhythms and Suppresses Its Own Expression |journal=Cell |date=June 1998 |volume=93 |issue=7 |pages=1207–1217 |doi=10.1016/s0092-8674(00)81464-6 |pmid=9657153 |s2cid=18992734 |doi-access=free }}
• {{cite journal |last1=Daniel |first1=Xavier |last2=Sugano |first2=Shoji |last3=Tobin |first3=Elaine M. |title=CK2 phosphorylation of CCA1 is necessary for its circadian oscillator function in Arabidopsis |journal=Proceedings of the National Academy of Sciences of the United States of America |date=2 March 2004 |volume=101 |issue=9 |pages=3292–3297 |doi=10.1073/pnas.0400163101 |pmid=14978263 |pmc=365783 |issn=0027-8424|doi-access=free |bibcode=2004PNAS..101.3292D }}

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Category:1944 births

Category:Living people

Category:Scientists from Louisville, Kentucky

Category:Oberlin College alumni

Category:Harvard University alumni

Category:University of California, Los Angeles faculty

Category:American women biologists

Category:21st-century American biologists