Sakthidevi M, Hoti SL, Kaliraj P. Functional analysis of a highly conserved abundant larval transcript-2 (alt-2) intron 2 repeat region of lymphatic filarial parasites.
INFECTION GENETICS AND EVOLUTION 2014;
24:177-82. [PMID:
24681262 DOI:
10.1016/j.meegid.2014.03.017]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 03/12/2014] [Accepted: 03/17/2014] [Indexed: 11/17/2022]
Abstract
The filarial-specific protein abundant larval transcript-2 (ALT-2) is expressed exclusively in the infective larval stage (L3) and is a crucial protein for establishing immunopathogenesis in human hosts. The alt-2 gene has a conserved minisatellite repeat (29 or 27bp) in intron 2 (IR2) whose significance within lymphatic filarial species is unknown. Here, we report the role of IR2 in the regulation of alt-2 gene expression using an in vitro model. Using electrophoretic mobility shift assays, we identified the presence of a putative nuclear protein binding region within IR2. Subsequent transient expression experiments in eukaryotic cell lines demonstrated that the IR2 downregulated the expression of a downstream luciferase reporter gene, which was further validated with RT-PCR. We therefore identify IR2 as a suppressor element that regulates L3 stage-specific expression of alt-2.
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