Tobacco Tsip1, a DnaJ-type Zn finger protein, is recruited to and potentiates Tsi1-mediated transcriptional activation.
Tobacco stress-induced1 (Tsi1) is an ethylene-responsive-element binding protein/APETALA2-type transcription factor that plays an important role in both biotic and abiotic stress signaling pathways. We show that Tsi1-interacting protein1 (Tsip1), a DnaJ-type Zn finger protein, interacts with Tsi1 in vitro and in yeast (Saccharomyces cerevisiae). The transcript level of Tsip1 in tobacco (Nicotiana tabacum) increased upon treatment with salicylic acid (SA), ethylene, gibberellic acid, NaCl, and virus challenge. Tsip1 appeared to be physically associated with the chloroplast surface but dissociated from it after SA treatment. Tsip1 colocalized and coimmunoprecipitated with Tsi1 in plant cells following SA treatment. Tsip1 expression increased Tsi1-mediated transcription and was able to functionally compensate for loss of the Tsi1 transcriptional activation domain through a direct interaction with Tsi1. Transgenic plants simultaneously coexpressing Tsi1 and Tsip1 displayed stronger pathogen resistance and salt tolerance than did transgenic plants expressing either Tsi1 or Tsip1 alone. Concurrent with this, the expression of a subset of stress-related genes was induced in a cooperative manner in Tsi1/Tsip1 transgenic plants. These results together implied that Tsi1 recruits Tsip1 to the promoters of stress-related genes to potentiate Tsi1-mediated transcriptional activation.
Ham
Byung-Kook
BK
School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
Park
Jeong Mee
JM
Lee
Suk-Bae
SB
Kim
Min Jung
MJ
Lee
In-Ju
IJ
Kim
Ki-Jeong
KJ
Kwon
Chang Seob
CS
Paek
Kyung-Hee
KH
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000378:metabolism / Q000821:virology; D011523:Protoplasts / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D020156:Salicylic Acid / Q000494:pharmacology; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism* / Q000502:physiology; D015533:Transcriptional Activation; D016335:Zinc Fingers / Q000502:physiology
D004268:DNA-Binding Proteins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C432450:Tsi1 protein, Nicotiana tabacum; D020156:Salicylic Acid