Dataset Information

Characterization of ?7/11, a functional prolactin-binding protein.

ABSTRACT: Prolactin is essential for normal mammary gland development and differentiation, and has been shown to promote tumor cell proliferation and chemotherapeutic resistance. Soluble isoforms of the prolactin receptor (PrlR) have been reported to regulate prolactin bioavailability by functioning as 'prolactin-binding proteins'. Included in this category is ?7/11, a product of alternate splicing of the PrlR primary transcript. However, the direct interactions of prolactin with ?7/11, and the resulting effect on cell behavior, have not been investigated. Herein, we demonstrate the ability of ?7/11 to bind prolactin using a novel proximity ligation assay and traditional immunoprecipitation techniques. Biochemical analyses demonstrated that ?7/11 was heavily glycosylated, similar to the extracellular domain of the primary PrlR, and that glycosylation regulated the cellular localization and secretion of ?7/11. Low levels of ?7/11 were detected in serum samples of healthy volunteers, but were undetectable in human milk samples. Expression of ?7/11 was also detected in six of the 62 primary breast tumor biopsies analyzed; however, no correlation was found with ?7/11 expression and tumor histotype or other patient demographics. Functional analysis demonstrated the ability of ?7/11 to inhibit prolactin-induced cell proliferation as well as alter prolactin-induced rescue of cell cycle arrest/early senescence events in breast epithelial cells. Collectively, these data demonstrate that ?7/11 is a novel regulatory mechanism of prolactin bioavailability and signaling.

SUBMITTER: Fleming JM

PROVIDER: S-EPMC3561765 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Characterization of Δ7/11, a functional prolactin-binding protein.

Fleming J M JM Ginsburg E E McAndrew C W CW Heger C D CD Cheston L L Rodriguez-Canales J J Vonderhaar B K BK Goldsmith P P

Journal of molecular endocrinology 20121231 1

Prolactin is essential for normal mammary gland development and differentiation, and has been shown to promote tumor cell proliferation and chemotherapeutic resistance. Soluble isoforms of the prolactin receptor (PrlR) have been reported to regulate prolactin bioavailability by functioning as 'prolactin-binding proteins'. Included in this category is Δ7/11, a product of alternate splicing of the PrlR primary transcript. However, the direct interactions of prolactin with Δ7/11, and the resulting ...[more]

PMID: 23048206

Similar Datasets

Project description:BACKGROUND:Lipid metabolism is pivotal for the growth of apicomplexan parasites. Lipid synthesis requires bulk carbon skeleton acyl-CoAs, the transport of which depends on the acyl-CoA binding protein (ACBP). In Neospora caninum, the causative agent of neosporosis, the FASII pathway is required for growth and pathogenicity. However, little is known about the fatty acid transport mechanism in N. caninum. METHODS:We have identified a cytosolic acyl-CoA binding protein, with highly conserved amino acid residues and a typical acyl-CoA binding domain in N. caninum. The recombinant NcACBP protein was expressed to verify the binding activities of NcACBP in vitro, and the heterologous expression of NcACBP in ?acbp yeast in vivo. Lipid extraction from ?NcACBP or the wild-type of N. caninum was analyzed by GC-MS or TLC. Furthermore, transcriptome analysis was performed to compare the gene expression in different strains. RESULTS:The NcACBP recombinant protein was able to specifically bind acyl-CoA esters in vitro. A yeast complementation assay showed that heterologous expression of NcACBP rescued the phenotypic defects in ?acbp yeast, indicating of the binding activity of NcACBP in vivo. The disruption of NcACBP did not perturb the parasite's growth but enhanced its pathogenicity in mice. The lipidomic analysis showed that disruption of NcACBP caused no obvious changes in the overall abundance and turnover of fatty acids while knockout resulted in the accumulation of triacylglycerol. Transcriptional analysis of ACBP-deficient parasites revealed differentially expressed genes involved in a wide range of biological processes such as lipid metabolism, posttranslational modification, and membrane biogenesis. CONCLUSIONS:Our study demonstrated that genetic ablation of NcACBP did not impair the survival and growth phenotype of N. caninum but enhanced its pathogenicity in mice. This deletion did not affect the overall fatty acid composition but modified the abundance of TAG. The loss of NcACBP resulted in global changes in the expression of multiple genes. This study provides a foundation for elucidating the molecular mechanism of lipid metabolism in N. caninum.

Dataset Information

Characterization of ?7/11, a functional prolactin-binding protein.

Publications

Characterization of Δ7/11, a functional prolactin-binding protein.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets