THAP and ATF-2 regulated sterol carrier protein-2 promoter activities in the larval midgut of the yellow fever mosquito, Aedes aegypti.

Abstract

Expression of sterol carrier protein-2 (SCP-2) in Aedes aegypti shows a distinct temporal/spatial pattern throughout the life cycle. In order to identify the transcription factors responsible for the larval temporal/spatial regulation of AeSCP-2 transcription, AeSCP-2 promoter activities were studied in vivo via transient transfection of promoter/reporter gene assays. Regulatory sequences upstream -1.3 kb of the transcription start site of AeSCP-2 were found to be critical for the in vivo temporal/spatial promoter activity. Interestingly, the -1.6 kb promoter sequence efficiently drove the larval midgut-specific siRNA expression, indicating that the -1.6 kb upstream sequence is sufficient for temporal/spatial AeSCP-2 transcriptional activity. Four transcription factors were identified in the midgut nuclear extract from feeding larvae via labeled -1.6/-1.3 kb DNA probe pull-down and proteomic analysis. Co-transfection of the promoter/reporter gene with inducible siRNA expression of each transcription factor was performed to confirm the regulatory function of individual transcription factor on AeSCP-2 transcriptional activities in the larval midgut. The results indicate that two of the identified transcription factors, Thanatos-associated protein (THAP) and activating transcription factor-2 (ATF-2), antagonistically control AeSCP-2 transcriptional activity in the midgut of feeding larvae via the regulatory sequences between -1.6 to -1.3 kb 5' upstream of the transcription start site. In vivo expression knockdown of THAP and ATF-2 resulted in significant changes in developmental progression, which may be partially due to their effects on AeSCP-2 expression.

• Authors: Rong Peng, Qiang Fu, Huazhu Hong, Tyler Schwaegler, Que Lan
• Journal: PloS one (PLoS One) Vol. 7 Issue 10 Pg. e46948 ( 2012) ISSN: 1932-6203 [Electronic] United States
• PMID: 23056538 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Activating Transcription Factor 2
• Carrier Proteins
• Insect Proteins
• sterol carrier proteins

Topics

• Activating Transcription Factor 2 (deficiency, genetics, metabolism)
• Aedes (genetics, growth & development, metabolism)
• Animals
• Carrier Proteins (genetics)
• Female
• Gene Expression Regulation
• Gene Knockdown Techniques
• Insect Proteins (deficiency, genetics, metabolism)
• Intestinal Mucosa (metabolism)
• Larva (genetics, growth & development, metabolism)
• Male
• Promoter Regions, Genetic
• Spatio-Temporal Analysis