Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in t...Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in the cellular membrane, storing as dormant forms. Upon exposure to environmental and developmental cues, these transcription factors are released from the membrane and translocated to the nucleus, where they regulate associated target genes. As this process skips both transcriptional and translational regulations, it guarantees prompt response to external and internal signals. Membrane- bound transcription factors （MTFs） undergo several unique steps that are not involved in the action of canonical nuclear transcription factors： proteolytic processing and intracellular movement. Recently, alternative splicing has also emerged as a mechanism to liberate MTFs from the cellular membranes, establishing an additional activation scheme independent of proteolytic processing. Multiple layers of MTF regulation add complexity to transcriptional regulatory scheme and ensure elaborate action of MTFs. In this review, we provide an overview of recent findings on MTFs in plants and highlight the molecular mechanisms underlying MTF liberation from cellular membranes with an emphasis on intracellular movement.展开更多
The phenomena of saltatory movements of intracellular particles (including organelles) in living cells have been repeatedly reported. The main feature of this kind of movement is the intermittency: the particle moves ...The phenomena of saltatory movements of intracellular particles (including organelles) in living cells have been repeatedly reported. The main feature of this kind of movement is the intermittency: the particle moves suddenly within a short duration of time and展开更多
Chloroplast photo-relocation movement is crucial for plant survival; however, the mechanism of this phenome- non is still poorly understood. Especially, the signal that goes from photoreceptor to chloroplast is unknow...Chloroplast photo-relocation movement is crucial for plant survival; however, the mechanism of this phenome- non is still poorly understood. Especially, the signal that goes from photoreceptor to chloroplast is unknown, although the photoreceptors （phototropin 1 and 2） have been identified and an actin structure （chloroplast actin filaments） has been characterized that is specific for chloroplast movement. Here, in gametophytes of the fern Adiantum capillus-veneris, gametophores of the moss Physcomiterella patens, and leaves of the seed plant Arabidopsis thaliana, we sought to characterize the signaling system by measuring the lifetime of the induced response. Chloroplast movements were induced by microbeam irradiation with high-intensity blue light and recorded. The lifetime of the avoidance state was measured as a lag time between switching off the beam and the loss of avoidance behavior, and that of the accumulation state was measured as the duration of accumulation behavior following the extinction of the beam. The lifetime for the avoidance response state is approximately 3-4rain and that for the accumulation response is 19-28 rain. These data suggest that the two responses are based on distinct signals.展开更多
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2013R1A1A1004831)research funds of Chonbuk National University in 2012
文摘Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in the cellular membrane, storing as dormant forms. Upon exposure to environmental and developmental cues, these transcription factors are released from the membrane and translocated to the nucleus, where they regulate associated target genes. As this process skips both transcriptional and translational regulations, it guarantees prompt response to external and internal signals. Membrane- bound transcription factors （MTFs） undergo several unique steps that are not involved in the action of canonical nuclear transcription factors： proteolytic processing and intracellular movement. Recently, alternative splicing has also emerged as a mechanism to liberate MTFs from the cellular membranes, establishing an additional activation scheme independent of proteolytic processing. Multiple layers of MTF regulation add complexity to transcriptional regulatory scheme and ensure elaborate action of MTFs. In this review, we provide an overview of recent findings on MTFs in plants and highlight the molecular mechanisms underlying MTF liberation from cellular membranes with an emphasis on intracellular movement.
文摘The phenomena of saltatory movements of intracellular particles (including organelles) in living cells have been repeatedly reported. The main feature of this kind of movement is the intermittency: the particle moves suddenly within a short duration of time and
基金supported in part by Grants-in-Aid for scientific research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (23120523 to M. W.)the Japan Society for the Promotion of Science (20227001, 25120721, and 25251033 to M. W.)
文摘Chloroplast photo-relocation movement is crucial for plant survival; however, the mechanism of this phenome- non is still poorly understood. Especially, the signal that goes from photoreceptor to chloroplast is unknown, although the photoreceptors （phototropin 1 and 2） have been identified and an actin structure （chloroplast actin filaments） has been characterized that is specific for chloroplast movement. Here, in gametophytes of the fern Adiantum capillus-veneris, gametophores of the moss Physcomiterella patens, and leaves of the seed plant Arabidopsis thaliana, we sought to characterize the signaling system by measuring the lifetime of the induced response. Chloroplast movements were induced by microbeam irradiation with high-intensity blue light and recorded. The lifetime of the avoidance state was measured as a lag time between switching off the beam and the loss of avoidance behavior, and that of the accumulation state was measured as the duration of accumulation behavior following the extinction of the beam. The lifetime for the avoidance response state is approximately 3-4rain and that for the accumulation response is 19-28 rain. These data suggest that the two responses are based on distinct signals.
