Limits...
Regulation of anti-Plasmodium immunity by a LITAF-like transcription factor in the malaria vector Anopheles gambiae.

Smith RC, Eappen AG, Radtke AJ, Jacobs-Lorena M - PLoS Pathog. (2012)

Bottom Line: Electrophoretic mobility shift assays identified specific LL3 DNA-binding motifs within the promoter of SRPN6, a gene that also mediates mosquito defense against Plasmodium.Further experiments indicated that these motifs play a direct role in LL3 regulation of SRPN6 expression.We conclude that LL3 is a transcription factor capable of modulating SRPN6 expression as part of the mosquito anti-Plasmodium immune response.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.

ABSTRACT
The mosquito is the obligate vector for malaria transmission. To complete its development within the mosquito, the malaria parasite Plasmodium must overcome the protective action of the mosquito innate immune system. Here we report on the involvement of the Anopheles gambiae orthologue of a conserved component of the vertebrate immune system, LPS-induced TNFα transcription factor (LITAF), and its role in mosquito anti-Plasmodium immunity. An. gambiae LITAF-like 3 (LL3) expression is up-regulated in response to midgut invasion by both rodent and human malaria parasites. Silencing of LL3 expression greatly increases parasite survival, indicating that LL3 is part of an anti-Plasmodium defense mechanism. Electrophoretic mobility shift assays identified specific LL3 DNA-binding motifs within the promoter of SRPN6, a gene that also mediates mosquito defense against Plasmodium. Further experiments indicated that these motifs play a direct role in LL3 regulation of SRPN6 expression. We conclude that LL3 is a transcription factor capable of modulating SRPN6 expression as part of the mosquito anti-Plasmodium immune response.

Show MeSH

Related in: MedlinePlus

PCR-assisted DNA-binding site selection reveals consensus LL3 DNA-binding motifs.(A) Experimental outline of the two methods [“cold” (non-radioactive) or “hot” (radioactive)] used to obtain consensus DNA binding sites for rLL3 by PCR-assisted DNA-binding site selection. Consensus motifs obtained from the “cold” method using a 10 bp degenerate sequence (B) or from the 20 bp degenerate sequences recovered using the “hot” method (C) are shown to the right. All recovered sequences used as input to generate the consensus motifs are listed in Table S2 and all motifs generated by the MEME program are displayed in Figure S4. EMSA: Electrophoretic Mobility-Shift Assay.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3475675&req=5

ppat-1002965-g004: PCR-assisted DNA-binding site selection reveals consensus LL3 DNA-binding motifs.(A) Experimental outline of the two methods [“cold” (non-radioactive) or “hot” (radioactive)] used to obtain consensus DNA binding sites for rLL3 by PCR-assisted DNA-binding site selection. Consensus motifs obtained from the “cold” method using a 10 bp degenerate sequence (B) or from the 20 bp degenerate sequences recovered using the “hot” method (C) are shown to the right. All recovered sequences used as input to generate the consensus motifs are listed in Table S2 and all motifs generated by the MEME program are displayed in Figure S4. EMSA: Electrophoretic Mobility-Shift Assay.

Mentions: Based on the characterization of LITAF as a transcription factor in other organisms, we examined the possibility that LL3 may also play a similar role in Anopheles and bind DNA. We used two different PCR-assisted DNA-binding site selection assays to identify DNA fragments able to bind to recombinant LL3 (Figure 4A). Following four rounds of selection for each method, the recovered sequences (Table S2) were then used as input for MEME analysis [16] to identify putative LL3-DNA binding motifs (Figure S4). Both methods produced multiple putative motifs.


Regulation of anti-Plasmodium immunity by a LITAF-like transcription factor in the malaria vector Anopheles gambiae.

Smith RC, Eappen AG, Radtke AJ, Jacobs-Lorena M - PLoS Pathog. (2012)

PCR-assisted DNA-binding site selection reveals consensus LL3 DNA-binding motifs.(A) Experimental outline of the two methods [“cold” (non-radioactive) or “hot” (radioactive)] used to obtain consensus DNA binding sites for rLL3 by PCR-assisted DNA-binding site selection. Consensus motifs obtained from the “cold” method using a 10 bp degenerate sequence (B) or from the 20 bp degenerate sequences recovered using the “hot” method (C) are shown to the right. All recovered sequences used as input to generate the consensus motifs are listed in Table S2 and all motifs generated by the MEME program are displayed in Figure S4. EMSA: Electrophoretic Mobility-Shift Assay.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3475675&req=5

ppat-1002965-g004: PCR-assisted DNA-binding site selection reveals consensus LL3 DNA-binding motifs.(A) Experimental outline of the two methods [“cold” (non-radioactive) or “hot” (radioactive)] used to obtain consensus DNA binding sites for rLL3 by PCR-assisted DNA-binding site selection. Consensus motifs obtained from the “cold” method using a 10 bp degenerate sequence (B) or from the 20 bp degenerate sequences recovered using the “hot” method (C) are shown to the right. All recovered sequences used as input to generate the consensus motifs are listed in Table S2 and all motifs generated by the MEME program are displayed in Figure S4. EMSA: Electrophoretic Mobility-Shift Assay.
Mentions: Based on the characterization of LITAF as a transcription factor in other organisms, we examined the possibility that LL3 may also play a similar role in Anopheles and bind DNA. We used two different PCR-assisted DNA-binding site selection assays to identify DNA fragments able to bind to recombinant LL3 (Figure 4A). Following four rounds of selection for each method, the recovered sequences (Table S2) were then used as input for MEME analysis [16] to identify putative LL3-DNA binding motifs (Figure S4). Both methods produced multiple putative motifs.

Bottom Line: Electrophoretic mobility shift assays identified specific LL3 DNA-binding motifs within the promoter of SRPN6, a gene that also mediates mosquito defense against Plasmodium.Further experiments indicated that these motifs play a direct role in LL3 regulation of SRPN6 expression.We conclude that LL3 is a transcription factor capable of modulating SRPN6 expression as part of the mosquito anti-Plasmodium immune response.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.

ABSTRACT
The mosquito is the obligate vector for malaria transmission. To complete its development within the mosquito, the malaria parasite Plasmodium must overcome the protective action of the mosquito innate immune system. Here we report on the involvement of the Anopheles gambiae orthologue of a conserved component of the vertebrate immune system, LPS-induced TNFα transcription factor (LITAF), and its role in mosquito anti-Plasmodium immunity. An. gambiae LITAF-like 3 (LL3) expression is up-regulated in response to midgut invasion by both rodent and human malaria parasites. Silencing of LL3 expression greatly increases parasite survival, indicating that LL3 is part of an anti-Plasmodium defense mechanism. Electrophoretic mobility shift assays identified specific LL3 DNA-binding motifs within the promoter of SRPN6, a gene that also mediates mosquito defense against Plasmodium. Further experiments indicated that these motifs play a direct role in LL3 regulation of SRPN6 expression. We conclude that LL3 is a transcription factor capable of modulating SRPN6 expression as part of the mosquito anti-Plasmodium immune response.

Show MeSH
Related in: MedlinePlus