Rabbit Anti-Human OSTF1 Polyclonal Antibody

The Nile tilapia represents an excellent model for osmoregulation study. Osmotic stress transcription factor 1 (OSTF1) identified in tilapia gill epithelium is a critical element of osmosensory signal transduction by means of transcriptional regulation. Thus, tight regulation of OSTF1 level is necessary for tilapia osmotic adaptation. microRNAs (miRNAs), have emerged as a crucial regulator of gene expression at post-transcriptional level. We reasoned that OSTF1 expression could be regulated by miRNAs. By bioinformatics analysis, we identified a putative miR-429 binding site in the OSTF1 mRNA. Interestingly, miR-429 is down-regulated in tilapia upon osmotic stress, consistent with OSTF1 protein up-regulation. miR-429 directly regulates OSTF1 expression by targeting its 3'-UTR, and inhibition of miR-429 substantially increases OSTF1 level in vivo. Moreover, miR-429 loss of function could influence the regulation of plasma osmolality and ion concentration responding to osmotic stress. Taken together, miR-429 is an endogenous regulator of OSTF1 expression, which participates in a regulatory circuit that allows rapid gene program transitions in response to osmotic stress. Crown Copyright (c) 2012 Published by Elsevier Inc. All rights reserved.

In many eukaryotic organisms, homeobox genes are important regulators that specify the cell fate and body plan in early embryogenesis. In this study, a gene designated OSTF1 (Oryza sativa transcription factor 1) encoding a homeodomain protein in rice was isolated and characterized. The encoded OSTF1, although sharing only approximately 51% sequence identity with other RD-GL2 members, contains four characteristic motifs (an N-terminal acidic region, a homeodomain, a truncated leucine zipper, and a START domain). OSTF1 was detected as a single copy gene in rice. The transcripts were absent in young panicle or mature spikelet before anthesis, but appeared very early in the pollinated grain with a transient profile. In vegetative tissues examined, expression was only detectable in root. In situ hybridization analysis on developing grains revealed that OSTF1 was strongly and uniformly expressed in the embryo at the globular stage and preferentially localized to the protoderm at 3-6 d after pollination. Expression was also detectable in the integument and throughout the endosperm. Although OSTF1 is not closely related to the remaining HD-GL2 members in sequences, this gene exhibits an analogous epidermis-p referential expression pattern.