Role of Tata box in signal transduction

TATA box is cis regulatory elements, which are present in DNA sequence.Its regulate the RNAP activity in gene expression.TATA box have significant regulatory effect on different metabolic pathway during stress condition.

1. TOPIC:- TATA - Box Rakesh sarma Ph.D research scholar Department of Plant physiology Institute of Agricultural science , BHU,Varanasi

2. TATA box   TATA box  was first  identified  in 1978 by American biochemist David  Hogness  and Gold-berg.   It is an example of a cis -regulatory element and has the core sequence 5' TATAAA 3'  TATA box is a DNA sequence that indicates where a genetic sequence can be read and decoded . It is a type of promoter sequence, which specifies to other molecules where transcription begins . Its located at 25-35 base pairs before the transcription start site of a gene.

3. Role of TATA box in RNA polymerase specificity TATA box sequence can act as a basal promoter. TATA sequence TATAAAAA specifically supported transcription by RNAP II in an unfractionated Drosophila nuclear extract, Where as the sequence TTTTTATA (the same sequence in reverse orientation) directed RNAP III transcription. the data indicate that T residues at positions 2 and 4 of the TATA box appear to be important determinants of RNAP III selectivity , whereas A residues at these positions favor RNAP II transcription Wang et al.,1996(nature genetics)

4. Marbach -bar et al., (Nature comunication,2013 )

5. TATA boxes in gene transcription and poly (A) tails in mRNA stability: New perspective on the effects of berberine Berberine (BBR) is a natural compound with variable pharmacological effects and a broad panel of target genes. BBR inhibits gene transcription by binding the TATA boxes in the transcriptional regulatory region, but it promotes higher levels of expression by targeting the poly (A) tails of mRNAs. The binding affinity sequence, from strong to weak, was TATA box > CAAT box > GC box . The ability of BBR to bind TT, TA, TTAA and TATA sequences increased with increasing repetitions of the target sequences. Berberine can use to cure severel genetic disease and cancer by its gene regulatory effect.

6. SAGA (Spt–Ada–Gcn5 Acetyltransferase ) is a transcriptional co-activator complex that regulates numerous cellular processes through the coordination of multiple post-translational histone modifications, including acetylation , deubiquitination , and chromatin recognition. the composition of the SAGA complex in plants are likely involved in the regulation of the inducible expression of genes under light, cold, drought, salt, and iron stress, although the functions of several of its components remain unknown.

7. SAGA molecule signaling during abiotc stress

8. TATA-box being only an eight-nucleotide sequence, individual position may determine specific aspects in promoter function  ( Kiran et al., 2006 ) showed that the seventh and eighth positions in the prototype core TATA-box TCACTATATATAG determine light-induced promoter expression. The presence of a G or C at these positions resulted in failure to form a light-specific transcription initiation complex. Substitution of T at the ninth position with G or C enhanced transcription from the promoter in transgenic tobacco ( Nicotiana tabacum ) plants. However, the 9G/C mutants in the presence of  lre failed to respond to phytochromes , sugar, and calcium signaling , in contrast to the prototype TATA-box with lre . The expression in both light and dark was enhanced equally as compared with the prototype promoter. The light-specific activation in transcription is affected by the intracellular level of Glc ( Acevedo-Hernandez et al., 2005 ), Ca 2+  ( Neuhaus et al., 1993 ;  Wu et al., 1996 ), and phytochromes ( Martinez-Garcia et al., 2000 ;  Kim et al., 2002 ;  Quail, 2002 )

9. Role of TATA box in phytochrome signaling

10. Rice transcription regulator OsWRKY13 influences the functioning of more than 500 genes in multiple signalling pathways, with roles in disease resistance, redox homeostasis, abiotic stress responses, and development. The most stringent definition for a WRKY binding site, a W-box, is a hexamer of TATAA(A/T), which is found in the promoter regions of many pathogenesis-related genes  . Rice OsWRKY13 is a potentially important transcriptional regulator involved in multiple physiological processes. It mediates disease resistance to bacterial blight caused by  Xanthomonas oryzae   pv .  oryzae   ( Xoo ) and fungal blast caused by  Magnaporthe grisea   through activation of salicylic acid (SA)-dependent pathways and suppression of jasmonic acid (JA)-dependent pathways;

11. The p68 is an evolutionarily conserved protein which plays pivotal roles in all aspect RNA metabolism processes. It is well established that helicases provides abiotic stress adaptation in plants but analysis of cis -regulatory elements present in the upstream regions is still infancy.  The promoter of  Psp68  was isolated by gene walking PCR from pea genomic DNA library constructed in BD genome walker kit. In silico analysis revealed that promoter of  Psp68 contained a TATA, a CAAT motif and also harbors some important stress and hormone associated cis regulatory elements, including E-box, AGAAA, GATA-box, ACGT, GAAAA and GTCTC. Functional analyses were performed by  Agrobacterium -mediated transient assay in tobacco leaves. Very high level of GUS activity was observed in agroinfiltrated tobacco leaves by the construct carrying the  Psp68 promoter::GUS, subjected to abiotic stress and exogenous hormonal treatments. Stress-inducible nature of Psp68  promoter opens possibility for the study of the gene regulation under stress condition. Therefore, may be useful in the field of agriculture and biotechnology.

12. Reference Yukawa, Y., Sugita, M., Choisne , N., Small, I., & Sugiura , M. (2000). The TATA motif, the CAA motif and the poly (T) transcription termination motif are all important for transcription re‐initiation on plant tRNA genes.  The Plant Journal ,  22 (5), 439-447. Chen, M., Chory , J., & Fankhauser , C. (2004). Light signal transduction in higher plants.  Annu . Rev. Genet. ,  38 , 87-117. Marbach -Bar, N., Ben-Noon, A., Ashkenazi, S., Harush , A. T. B., Avnit-Sagi , T., Walker, M. D., & Dikstein , R. (2013). Disparity between microRNA levels and promoter strength is associated with initiation rate and Pol II pausing. Nature communications ,  Yamamoto, Y. Y., Yoshitsugu , T., Sakurai, T., Seki, M., Shinozaki, K., & Obokata , J. (2009). Heterogeneity of Arabidopsis core promoters revealed by high‐density TSS analysis.  The Plant Journal ,  60 (2), 350-362.