TOPIC:- TATA - Box

Rakesh sarma

Ph.D research scholar

Department of Plant physiology

Institute of Agricultural science,

BHU,Varanasi

TATA box TATA box was first identified in 1978 by American biochemistDavid Hogness and Gold-berg.

It is an example of a cis-regulatory element and has the coresequence 5' TATAAA 3'

TATA box is a DNA sequence that indicates where a geneticsequence can be read and decoded.

It is a type of promoter sequence, which specifies to othermolecules where transcription begins.

Its located at 25-35 base pairs before the transcription start site ofa gene.

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 sequencein reverse orientation) directed RNAP III transcription.

the data indicate that T residues at positions 2 and 4 ofthe TATA box appear to be important determinants ofRNAP III selectivity ,

whereas A residues at these positions favor RNAP IItranscription

Wang et al.,1996(nature genetics)

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

TATA boxes in gene transcription and poly (A) tails inmRNA stability: New perspective on the effects ofberberine

• Berberine (BBR) is a natural compound with variablepharmacological effects and a broad panel of target genes.

• BBR inhibits gene transcription by binding the TATA boxes in thetranscriptional regulatory region, but it promotes higher levels ofexpression 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 andTATA sequences increased with increasing repetitions of the targetsequences.

• Berberine can use to cure severel genetic disease and cancer by itsgene regulatory effect.

• SAGA (Spt–Ada–Gcn5 Acetyltransferase) is a transcriptionalco-activator complex that regulates numerous cellularprocesses through the coordination of multiple post-translational histone modifications, including acetylation,deubiquitination, and chromatin recognition.

• the composition of the SAGA complex in plants are likelyinvolved in the regulation of the inducible expression of genesunder light, cold, drought, salt, and iron stress, although thefunctions of several of its components remain unknown.

SAGA molecule signaling during abiotcstress

TATA-box being only an eight-nucleotide sequence, individual position may determinespecific aspects in promoter function

(Kiran et al., 2006) showed that the seventh and eighth positions in the prototype coreTATA-box TCACTATATATAG determine light-induced promoter expression.

The presence of a G or C at these positions resulted in failure to form a light-specifictranscription initiation complex.

Substitution of T at the ninth position with G or C enhanced transcription from thepromoter 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 withlre.

The expression in both light and dark was enhanced equally as compared with theprototype promoter. The light-specific activation in transcription is affected by theintracellular level of Glc (Acevedo-Hernandez et al., 2005), Ca2+ (Neuhaus et al., 1993; Wuet al., 1996), and phytochromes (Martinez-Garcia et al., 2000; Kim et al., 2002; Quail,2002)

Role of TATA box in phytochromesignaling

Rice transcription regulator OsWRKY13 influences thefunctioning of more than 500 genes in multiple signallingpathways, 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 promoterregions of many pathogenesis-related genes .

Rice OsWRKY13 is a potentially important transcriptionalregulator involved in multiple physiological processes. It mediatesdisease resistance to bacterial blight caused by Xanthomonasoryzae pv. oryzae (Xoo) and fungal blast caused by Magnaporthegrisea through activation of salicylic acid (SA)-dependentpathways and suppression of jasmonic acid (JA)-dependentpathways;

The p68 is an evolutionarily conserved protein which plays pivotal rolesin all aspect RNA metabolism processes.

It is well established that helicases provides abiotic stress adaptation inplants but analysis of cis-regulatory elements present in the upstreamregions is still infancy.

The promoter of Psp68 was isolated by gene walking PCR from peagenomic DNA library constructed in BD genome walker kit. In silico analysisrevealed that promoter of Psp68 contained a TATA, a CAAT motif and alsoharbors some important stress and hormone associated cis regulatoryelements, including E-box, AGAAA, GATA-box, ACGT, GAAAA and GTCTC.

Functional analyses were performed by Agrobacterium-mediatedtransient assay in tobacco leaves. Very high level of GUS activity wasobserved in agroinfiltrated tobacco leaves by the construct carryingthe Psp68promoter::GUS, subjected to abiotic stress and exogenoushormonal treatments. Stress-inducible nature of Psp68 promoter openspossibility for the study of the gene regulation under stress condition.Therefore, may be useful in the field of agriculture and biotechnology.

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 fortranscription re‐initiation on plant tRNA genes. The Plant Journal, 22(5), 439-447.

• Chen, M., Chory, J., & Fankhauser, C. (2004). Light signal transduction in higherplants. 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 andpromoter strength is associated with initiation rate and Pol II pausing.Naturecommunications,

• Yamamoto, Y. Y., Yoshitsugu, T., Sakurai, T., Seki, M., Shinozaki, K., & Obokata, J.(2009). Heterogeneity of Arabidopsis core promoters revealed by high‐density TSSanalysis. The Plant Journal, 60(2), 350-362.