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MaFA is a dedicated activator of the insulin gene in vivo.

Artner, Isabella LU ; Hang, Yan; Guo, Min; Gu, Guoqiang and Stein, Roland (2008) In Journal of Endocrinology May 30. p.271-279
Abstract
As successful generation of insulin producing cells could be used for diabetes treatment, a concerted effort is being made to understand the molecular programs underlying islet beta cell formation and function. The closely related MafA and MafB transcription factors are both key mammalian beta cell regulators. MafA and MafB are co-expressed in insulin+ beta cells during embryogenesis, while in the adult pancreas MafA is only produced in beta cells and MafB in glucagon+ alpha cells. MafB-/- animals are also deficient in insulin+ and glucagon+ cell production during embryogenesis. However, only MafA over-expression selectively induced endogenous Insulin mRNA production in cell line based assays, while MafB specifically promoted Glucagon... (More)
As successful generation of insulin producing cells could be used for diabetes treatment, a concerted effort is being made to understand the molecular programs underlying islet beta cell formation and function. The closely related MafA and MafB transcription factors are both key mammalian beta cell regulators. MafA and MafB are co-expressed in insulin+ beta cells during embryogenesis, while in the adult pancreas MafA is only produced in beta cells and MafB in glucagon+ alpha cells. MafB-/- animals are also deficient in insulin+ and glucagon+ cell production during embryogenesis. However, only MafA over-expression selectively induced endogenous Insulin mRNA production in cell line based assays, while MafB specifically promoted Glucagon expression. Here we analyzed if these factors were sufficient to induce insulin+ and/or glucagon+ cell formation within embryonic endoderm using the chick in ovo electroporation assay. Ectopic expression of MafA, but not MafB, promoted Insulin production, however neither MafA nor MafB were capable of inducing Glucagon. Co-electroporation of MafA with the Ngn3 transcription factor resulted in the development of more organized cell clusters containing both insulin and glucagon producing cells. Analysis of chimeric proteins of MafA and MafB demonstrated that chick Insulin activation depended on sequences within the MafA C-terminal DNA binding domain. MafA was also bound to Insulin and Glucagon transcriptional control sequences in mouse embryonic pancreas and beta cell lines. Collectively, these results demonstrate a unique ability for MafA to independently activate Insulin transcription. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Endocrinology
volume
May 30
pages
271 - 279
publisher
Society for Endocrinology
external identifiers
  • wos:000259025800002
  • pmid:18515495
  • scopus:51349103007
ISSN
1479-6805
DOI
10.1677/JOE-08-0063
language
English
LU publication?
yes
id
43e78980-65bc-40fd-8955-0d8988476068 (old id 1169361)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/18515495?dopt=Abstract
date added to LUP
2008-07-02 10:57:00
date last changed
2017-09-24 04:38:49
@article{43e78980-65bc-40fd-8955-0d8988476068,
  abstract     = {As successful generation of insulin producing cells could be used for diabetes treatment, a concerted effort is being made to understand the molecular programs underlying islet beta cell formation and function. The closely related MafA and MafB transcription factors are both key mammalian beta cell regulators. MafA and MafB are co-expressed in insulin+ beta cells during embryogenesis, while in the adult pancreas MafA is only produced in beta cells and MafB in glucagon+ alpha cells. MafB-/- animals are also deficient in insulin+ and glucagon+ cell production during embryogenesis. However, only MafA over-expression selectively induced endogenous Insulin mRNA production in cell line based assays, while MafB specifically promoted Glucagon expression. Here we analyzed if these factors were sufficient to induce insulin+ and/or glucagon+ cell formation within embryonic endoderm using the chick in ovo electroporation assay. Ectopic expression of MafA, but not MafB, promoted Insulin production, however neither MafA nor MafB were capable of inducing Glucagon. Co-electroporation of MafA with the Ngn3 transcription factor resulted in the development of more organized cell clusters containing both insulin and glucagon producing cells. Analysis of chimeric proteins of MafA and MafB demonstrated that chick Insulin activation depended on sequences within the MafA C-terminal DNA binding domain. MafA was also bound to Insulin and Glucagon transcriptional control sequences in mouse embryonic pancreas and beta cell lines. Collectively, these results demonstrate a unique ability for MafA to independently activate Insulin transcription.},
  author       = {Artner, Isabella and Hang, Yan and Guo, Min and Gu, Guoqiang and Stein, Roland},
  issn         = {1479-6805},
  language     = {eng},
  pages        = {271--279},
  publisher    = {Society for Endocrinology},
  series       = {Journal of Endocrinology},
  title        = {MaFA is a dedicated activator of the insulin gene in vivo.},
  url          = {http://dx.doi.org/10.1677/JOE-08-0063},
  volume       = {May 30},
  year         = {2008},
}