TY - JOUR
T1 - MBF2 is a tissue- and stage-specific coactivator that is regulated at the step of nuclear transport in the silkworm Bombyx mori
AU - Liu, Qing Xin
AU - Ueda, Hitoshi
AU - Hirose, Susumu
N1 - Funding Information:
We thank Yash Hiromi for the FITC-anti-HRP antibody, G.-C. Sun for the anti-BmFTZ-F1 antibody, Marek Jindra for the anti-MBF1 antibody, and Kazuhiko Umesono for pERREx3-tk-lnc. This work was supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Science, Sports, and Culture of Japan. Q.-X. Liu was supported by Japan Society for the Promotion of Science.
PY - 2000/9/15
Y1 - 2000/9/15
N2 - Coactivators MBF1 and MBF2 mediate BmFTZ-F1-dependent transcriptional activation in vitro by interconnecting BmFTZ-F1, TATA binding protein TBP, and TFIIA. Here, we analyzed temporal and spatial expression patterns of MBF2 during embryonic and larval development of the silkworm Bombyx mori. MBF2 was detected in unfertilized eggs and embryos until stage 26. In stage 22 embryos, MBF1, MBF2, and BmFTZ-F1 colocalize in neural cells. During the larval stage, MBF2 was not expressed in the fat body and trachea. In the silk gland, MBF2 mRNA was constitutively expressed, but MBF2 protein appeared in the period between the second day and the molting D3 stage in both the third and the fourth instars and then disappeared. MBF2 was also detected on the second and third days of the fifth instar. Immunostaining during the fourth molt showed that MBF1, MBF2, and BmFTZ-F1 localize in the nucleus only at the D3 stage, while the two cofactors are present in the cytoplasm at other stages. Immunoprecipitation experiments suggested that MBF1, MBF2, and BmFTZ-F1 form a complex at the D3 stage. Transient expression of these factors in Schneider cell line 2 revealed that MBF1 and MBF2 localize to the nucleus and enhance BmFTZ-F1-dependent transcription only when all three factors are present. These data illustrate the functional regulation of MBF1 and MBF2 at the step of nuclear transport and implicate MBF2 in tissue- and stage-specific transcription. (C) 2000 Academic Press.
AB - Coactivators MBF1 and MBF2 mediate BmFTZ-F1-dependent transcriptional activation in vitro by interconnecting BmFTZ-F1, TATA binding protein TBP, and TFIIA. Here, we analyzed temporal and spatial expression patterns of MBF2 during embryonic and larval development of the silkworm Bombyx mori. MBF2 was detected in unfertilized eggs and embryos until stage 26. In stage 22 embryos, MBF1, MBF2, and BmFTZ-F1 colocalize in neural cells. During the larval stage, MBF2 was not expressed in the fat body and trachea. In the silk gland, MBF2 mRNA was constitutively expressed, but MBF2 protein appeared in the period between the second day and the molting D3 stage in both the third and the fourth instars and then disappeared. MBF2 was also detected on the second and third days of the fifth instar. Immunostaining during the fourth molt showed that MBF1, MBF2, and BmFTZ-F1 localize in the nucleus only at the D3 stage, while the two cofactors are present in the cytoplasm at other stages. Immunoprecipitation experiments suggested that MBF1, MBF2, and BmFTZ-F1 form a complex at the D3 stage. Transient expression of these factors in Schneider cell line 2 revealed that MBF1 and MBF2 localize to the nucleus and enhance BmFTZ-F1-dependent transcription only when all three factors are present. These data illustrate the functional regulation of MBF1 and MBF2 at the step of nuclear transport and implicate MBF2 in tissue- and stage-specific transcription. (C) 2000 Academic Press.
KW - Coactivator
KW - Nuclear receptor
KW - Nuclear transport
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U2 - 10.1006/dbio.2000.9836
DO - 10.1006/dbio.2000.9836
M3 - Article
C2 - 10985861
AN - SCOPUS:0034665633
VL - 225
SP - 437
EP - 446
JO - Developmental Biology
JF - Developmental Biology
SN - 0012-1606
IS - 2
ER -