Mcknight, Thomas individual record
Professor and Head
overview

My lab is currently investigating mechanisms that regulate telomerase activity in plants. We previously showed that the pattern of telomerase expression in plants is remarkably similar to the pattern seen in humans, despite fundamental differences in development between plants and animals. Telomerase is abundantly expressed in reproductive organs but is undetectable in most vegetative organs (Fitzgerald et al., 1996). Additionally, telomerase can be induced in leaves and other vegetative organs by exposure to exogenous auxin.



To isolate genes that regulate telomerase, we screened a large population of activation tagged lines of Arabidopsis thaliana, and found that several lines that ectopically express telomerase in leaves. The first line we characterized over-expressed a gene encoding a small zinc finger transcription factor we designated TELOMERASE ACTIVATOR 1 (Ren et al., 2004). This factor does not bind to the promoter for TERT, which encodes the catalytically active subunit of telomerase. Instead, it binds to and activates transcription of BT2, a gene encoding a component of a ubiquitin ligase (Ren et al., 2007). Our working model is that the BT2 ubiquitin ligase marks a telomerase repressor for destruction, thereby allowing expression of telomerase. Efforts in the lab are currently focused on identifying the presumed telomerase repressor protein and other proteins that interact with BT2.

education and training
selected publications
Academic Articles41
  • Mandal, S., Ji, W., & McKnight, T. D. (2020). Candidate Gene Networks for Acylsugar Metabolism and Plant Defense in Wild Tomato Solanum pennellii. 32(1), tpc.00552.2019-99.
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  • Misra, A., McKnight, T. D., & Mandadi, K. K (2018). Bromodomain proteins GTE9 and GTE11 are essential for specific BT2-mediated sugar and ABA responses in Arabidopsis thaliana.. Plant Mol Biol. 96(4-5), 393-402.
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  • Robinson, W. D., Park, J., Tran, H. T., Del Vecchio, H. A., Ying, S., Zins, J. L., ... Plaxton, W. C. (2012). The secreted purple acid phosphatase isozymes AtPAP12 and AtPAP26 play a pivotal role in extracellular phosphate-scavenging by Arabidopsis thaliana. 63(18), 6531-6542.
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  • Gngora-Castillo, E., Childs, K. L., Fedewa, G., Hamilton, J. P., Liscombe, D. K., Magallanes-Lundback, M., ... Buell, C. R. (2012). Development of transcriptomic resources for interrogating the biosynthesis of monoterpene indole alkaloids in medicinal plant species.. PLoS One. 7(12), e52506-e52506.
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  • Mandadi, K. K., Misra, A., Ren, S., & McKnight, T. D (2009). BT2, a BTB protein, mediates multiple responses to nutrients, stresses, and hormones in Arabidopsis.. Plant Physiol. 150(4), 1930-1939.
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Conference Papers7
  • Patel, K., Lockless, S., Thomas, B., & McKnight, T. D. (1999). Secreted purple acid phosphatase from Arabidopsis thaliana. 19, 373-375.
  • Patel, K., Lockless, S., Thomas, B., & McKnight, T. D. (1996). A secreted purple acid phosphatase from Arabidopsis.. 111(2), 271-271.
  • Hua, L., Henning, D., Patel, K., Brown, L., Teoh, T., & McKnight, T. D. (1996). Molecular biology of camptothecin production. 111(2), 618-618.
  • PATEL, K., LU, H., HENNING, D., & MCKNIGHT, T. D. (1995). MOLECULAR-BIOLOGY OF CAMPTOTHECIN BIOSYNTHESIS. 108(2), 138-138.
  • MCKNIGHT, T. D., & HENNING, D. D. (1994). CAMPTOTHECIN, AN ANTI-CANCER ALKALOID FROM CAMPTOTHECA-ACUMINATA (NYSSACEAE). 48, 149-158.
chaired theses and dissertations
Email
tdmcknight@tamu.edu
First Name
Thomas
Last Name
Mcknight
mailing address
Texas A&M University; Biology; 3258 TAMU
College Station, TX 77843-3258
USA