ISL1 physically interacts with BETA2 to promote insulin gene transcriptional synergy in non-beta cells.
ISL1 is a LIM homeodomain protein that plays an important role in insulin gene transcriptional activation and islet cell formation. BETA2 is a transcription factor in the basic helix-loop-helix (bHLH) family, which activates expression of tissue-specific genes in several developmental systems. In this study, we investigated the functional and physical interactions of ISL1 and BETA2 in promoting insulin gene transcription in non-beta cells. Using the luciferase assay, we demonstrated that ISL1 and BETA2 could activate insulin gene transcription synergistically. Co-immunoprecipitation also supported that ISL1 and BETA2 appear in one complex and this physical interaction mediates the synergy between these two proteins.
Peng
Si-Yang
SY
Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University, Beijing 100083, China.
Wang
Wei-Ping
WP
Meng
Jun
J
Li
Tao
T
Zhang
Hui
H
Li
Yan-Ming
YM
Chen
Ping
P
Ma
Kang-Tao
KT
Zhou
Chun-Yan
CY
D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000235:genetics* / Q000378:metabolism; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000502:physiology*; D014162:Transfection
D051792:Basic Helix-Loop-Helix Proteins; D018398:Homeodomain Proteins; D007328:Insulin; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; C093970:NEUROD1 protein, human; C063843:insulin gene enhancer binding protein Isl-1