The cauliflower mosaic virus 35S promoter is composed of several cis-elements, each of which confers a different expression pattern in transgenic tobacco. One such cis-element, activation sequence (as)-1 (-83 to -63) mediates preferential expression in root. The element contains a tandem repeat of the motif TGACG, that is crucial for as-1 function and binding of a tobacco nuclear factor, activation sequence factor (ASF)-1. Two other TGACG-containing cis-elements from plant promoters were identified by a computer assisted search of a gene bank. These cis-elements, hex-1 from the wheat histone H3 promoter and nos-1 from the nopaline synthase promoter of T-DNA, also bind ASF-1. Another tobacco nuclear factor, designated hex-i-specific binding factor (HSBF), binds only to hex-1, A tobacco cDNA library was screened for DNA-binding proteins using hex-1as a binding probe and two types of clones encoding hex-1-binding proteins were isolated. Based on their binding specificities to as-1, hex-1, and nos-1, the encoded DNA-binding proteins, named TGA1a and TGA1b, appear to correspond to ASF-1 and HSBF, respectively. Both TGA1a and TGA1b are bZIP proteins. The TGA1a mRNA level is much higher in root than in leaf. TGA1a can function as an as-1-specific transcription activator in a HeLa cell in vitro system as well as a wheat germ in vitro system. In both systems, TGA1a stimulates transcription by increasing the number of preinitiation complexes. When microinjected into cotyledon cells of transgenic tobacco plants carrying a promoter linked to as-I, TGA1a can induce the expression of the promoter. Judging from these results, TGA1a is likely to be the factor that is responsible for the as-1 function in vivo. Such a factor is present in leaf cells in a limiting concentration. Although the bZIP domain of TGA1a is sufficient for the specific binding to its target site, another domain (DS domain) increases the apparent DNA-binding affinity by stabilizing the dimeric form of TGA1a. The N-terminal region of TGA1a, which is enriched in acidic residues, appears to be essential for transactivation in vivo. However, when assayed in a HeLa cell in vitro system, most parts of the protein except the bZIP domain seem dispensable for activity.
","abstract_html":"<p>The cauliflower mosaic virus 35S promoter is composed of several cis-elements, each of which confers a different expression pattern in transgenic tobacco. One such cis-element, activation sequence (as)-1 (-83 to -63) mediates preferential expression in root. The element contains a tandem repeat of the motif TGACG, that is crucial for as-1 function and binding of a tobacco nuclear factor, activation sequence factor (ASF)-1. Two other TGACG-containing cis-elements from plant promoters were identified by a computer assisted search of a gene bank. These cis-elements, hex-1 from the wheat histone H3 promoter and nos-1 from the nopaline synthase promoter of T-DNA, also bind ASF-1. Another tobacco nuclear factor, designated hex-i-specific binding factor (HSBF), binds only to hex-1, A tobacco cDNA library was screened for DNA-binding proteins using hex-1as a binding probe and two types of clones encoding hex-1-binding proteins were isolated. Based on their binding specificities to as-1, hex-1, and nos-1, the encoded DNA-binding proteins, named TGA1a and TGA1b, appear to correspond to ASF-1 and HSBF, respectively. Both TGA1a and TGA1b are bZIP proteins. The TGA1a mRNA level is much higher in root than in leaf. TGA1a can function as an as-1-specific transcription activator in a HeLa cell in vitro system as well as a wheat germ in vitro system. In both systems, TGA1a stimulates transcription by increasing the number of preinitiation complexes. When microinjected into cotyledon cells of transgenic tobacco plants carrying a promoter linked to as-I, TGA1a can induce the expression of the promoter. Judging from these results, TGA1a is likely to be the factor that is responsible for the as-1 function in vivo. Such a factor is present in leaf cells in a limiting concentration. Although the bZIP domain of TGA1a is sufficient for the specific binding to its target site, another domain (DS domain) increases the apparent DNA-binding affinity by stabilizing the dimeric form of TGA1a. The N-terminal region of TGA1a, which is enriched in acidic residues, appears to be essential for transactivation in vivo. However, when assayed in a HeLa cell in vitro system, most parts of the protein except the bZIP domain seem dispensable for activity.</p>","abstract_has_math":false,"creators":["Katagiri, Fumiaki"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Nam-Hai Chua"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1991,"date_issued":"1991-01-01T08:00:00Z","date_published":"1991-01-01T08:00:00Z","updated_at":"2026-07-24T04:11:11Z","subjects":["35S promoter","as-1 element","TGA1a","ASF-1","bZIP transcription factor","root-specific expression","Life Sciences"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.rockefeller.edu/student_theses_and_dissertations/375","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Nam-Hai Chua"]},{"key":"dc:creator","label":"Author","values":["Katagiri, Fumiaki"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["35S promoter","as-1 element","TGA1a","ASF-1","bZIP transcription factor","root-specific expression","Life Sciences"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.rockefeller.edu/student_theses_and_dissertations/375"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The cauliflower mosaic virus 35S promoter is composed of several cis-elements, each of which confers a different expression pattern in transgenic tobacco. One such cis-element, activation sequence (as)-1 (-83 to -63) mediates preferential expression in root. The element contains a tandem repeat of the motif TGACG, that is crucial for as-1 function and binding of a tobacco nuclear factor, activation sequence factor (ASF)-1. Two other TGACG-containing cis-elements from plant promoters were identified by a computer assisted search of a gene bank. These cis-elements, hex-1 from the wheat histone H3 promoter and nos-1 from the nopaline synthase promoter of T-DNA, also bind ASF-1. Another tobacco nuclear factor, designated hex-i-specific binding factor (HSBF), binds only to hex-1, A tobacco cDNA library was screened for DNA-binding proteins using hex-1as a binding probe and two types of clones encoding hex-1-binding proteins were isolated. Based on their binding specificities to as-1, hex-1, and nos-1, the encoded DNA-binding proteins, named TGA1a and TGA1b, appear to correspond to ASF-1 and HSBF, respectively. Both TGA1a and TGA1b are bZIP proteins. The TGA1a mRNA level is much higher in root than in leaf. TGA1a can function as an as-1-specific transcription activator in a HeLa cell in vitro system as well as a wheat germ in vitro system. In both systems, TGA1a stimulates transcription by increasing the number of preinitiation complexes. When microinjected into cotyledon cells of transgenic tobacco plants carrying a promoter linked to as-I, TGA1a can induce the expression of the promoter. Judging from these results, TGA1a is likely to be the factor that is responsible for the as-1 function in vivo. Such a factor is present in leaf cells in a limiting concentration. Although the bZIP domain of TGA1a is sufficient for the specific binding to its target site, another domain (DS domain) increases the apparent DNA-binding affinity by stabilizing the dimeric form of TGA1a. The N-terminal region of TGA1a, which is enriched in acidic residues, appears to be essential for transactivation in vivo. However, when assayed in a HeLa cell in vitro system, most parts of the protein except the bZIP domain seem dispensable for activity.
"]},{"key":"dc:title","label":"Title","values":["Structure and Function Analysis of a Plant Transcription Activator"]}]}],"canonical_facts":{"dc:contributor":["Nam-Hai Chua"],"dc:creator":["Katagiri, Fumiaki"],"dc:description.abstract":["The cauliflower mosaic virus 35S promoter is composed of several cis-elements, each of which confers a different expression pattern in transgenic tobacco. One such cis-element, activation sequence (as)-1 (-83 to -63) mediates preferential expression in root. The element contains a tandem repeat of the motif TGACG, that is crucial for as-1 function and binding of a tobacco nuclear factor, activation sequence factor (ASF)-1. Two other TGACG-containing cis-elements from plant promoters were identified by a computer assisted search of a gene bank. These cis-elements, hex-1 from the wheat histone H3 promoter and nos-1 from the nopaline synthase promoter of T-DNA, also bind ASF-1. Another tobacco nuclear factor, designated hex-i-specific binding factor (HSBF), binds only to hex-1, A tobacco cDNA library was screened for DNA-binding proteins using hex-1as a binding probe and two types of clones encoding hex-1-binding proteins were isolated. Based on their binding specificities to as-1, hex-1, and nos-1, the encoded DNA-binding proteins, named TGA1a and TGA1b, appear to correspond to ASF-1 and HSBF, respectively. Both TGA1a and TGA1b are bZIP proteins. The TGA1a mRNA level is much higher in root than in leaf. TGA1a can function as an as-1-specific transcription activator in a HeLa cell in vitro system as well as a wheat germ in vitro system. In both systems, TGA1a stimulates transcription by increasing the number of preinitiation complexes. When microinjected into cotyledon cells of transgenic tobacco plants carrying a promoter linked to as-I, TGA1a can induce the expression of the promoter. Judging from these results, TGA1a is likely to be the factor that is responsible for the as-1 function in vivo. Such a factor is present in leaf cells in a limiting concentration. Although the bZIP domain of TGA1a is sufficient for the specific binding to its target site, another domain (DS domain) increases the apparent DNA-binding affinity by stabilizing the dimeric form of TGA1a. The N-terminal region of TGA1a, which is enriched in acidic residues, appears to be essential for transactivation in vivo. However, when assayed in a HeLa cell in vitro system, most parts of the protein except the bZIP domain seem dispensable for activity.
"],"dc:identifier":["https://digitalcommons.rockefeller.edu/student_theses_and_dissertations/375"],"dc:subject":["35S promoter","as-1 element","TGA1a","ASF-1","bZIP transcription factor","root-specific expression","Life Sciences"],"dc:title":["Structure and Function Analysis of a Plant Transcription Activator"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T04:11:11Z"}