RNA-binding protein PSPC1 promotes the differentiation-dependent nuclear export of adipocyte RNAs
Jiexin Wang, Prashant Rajbhandari, Andrey Damianov, Areum Han, Tamer Sallam, Hironori Waki, Claudio J. Villanueva, Stephen D. Lee, Ronni Nielsen, Susanne Mandrup, Karen Reue, Stephen G. Young, Julian Whitelegge, Enrique Saez, Douglas L. Black, Peter Tontonoz
Jiexin Wang, Prashant Rajbhandari, Andrey Damianov, Areum Han, Tamer Sallam, Hironori Waki, Claudio J. Villanueva, Stephen D. Lee, Ronni Nielsen, Susanne Mandrup, Karen Reue, Stephen G. Young, Julian Whitelegge, Enrique Saez, Douglas L. Black, Peter Tontonoz
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Research Article Metabolism

RNA-binding protein PSPC1 promotes the differentiation-dependent nuclear export of adipocyte RNAs

Abstract

A highly orchestrated gene expression program establishes the properties that define mature adipocytes, but the contribution of posttranscriptional factors to the adipocyte phenotype is poorly understood. Here we have shown that the RNA-binding protein PSPC1, a component of the paraspeckle complex, promotes adipogenesis in vitro and is important for mature adipocyte function in vivo. Cross-linking and immunoprecipitation followed by RNA sequencing revealed that PSPC1 binds to intronic and 3′-untranslated regions of a number of adipocyte RNAs, including the RNA encoding the transcriptional regulator EBF1. Purification of the paraspeckle complex from adipocytes further showed that PSPC1 associates with the RNA export factor DDX3X in a differentiation-dependent manner. Remarkably, PSPC1 relocates from the nucleus to the cytoplasm during differentiation, coinciding with enhanced export of adipogenic RNAs. Mice lacking PSPC1 in fat displayed reduced lipid storage and adipose tissue mass and were resistant to diet-induced obesity and insulin resistance due to a compensatory increase in energy expenditure. These findings highlight a role for PSPC1-dependent RNA maturation in the posttranscriptional control of adipose development and function.

Authors

Jiexin Wang, Prashant Rajbhandari, Andrey Damianov, Areum Han, Tamer Sallam, Hironori Waki, Claudio J. Villanueva, Stephen D. Lee, Ronni Nielsen, Susanne Mandrup, Karen Reue, Stephen G. Young, Julian Whitelegge, Enrique Saez, Douglas L. Black, Peter Tontonoz

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Figure 3

PSPC1 selectively interacts with certain adipocyte RNAs.

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PSPC1 selectively interacts with certain adipocyte RNAs. (A) Immunoblot ...
(A) Immunoblot analysis of Flag-tagged PSPC1 protein (Fl-Pspc1) in the whole cell lysate and immunopurified products. Differentiated 10T1/2 adipocytes stably expressing Fl-Pspc1 or vector were used. Following UV cross-linking, 3X Flag antibody was used for IP. (B) Real-time PCR analysis of target transcript levels in Flag-immunoprecipitated samples. RNA was isolated from input and IP samples described in A. Values represent the amount of each transcript in the IP sample normalized to its amount in the input sample. Neat1 serves as a positive control; cyclophilin and 36B4 serve as negative controls. Results are representative of 2 independent experiments. (C) Immunoblot analysis of endogenous PSPC1 protein in the whole cell lysate and immunopurified products. 10T1/2 adipocytes on differentiation day 6 were used. Following UV cross-linking, endogenous PSPC1 antibody and IgG isotype control antibody were used for IP. (D) Real-time PCR analysis of target transcript levels in the PSPC1-immunoprecipitated sample. RNA was isolated from input and IP samples described in C. Values represent the amount of each transcript in the IP sample normalized to its amount in the input sample. Neat1 serves as a positive control; cyclophilin and 36B4 serve as negative controls. Results are representative of 2 independent experiments. Error bars represent mean + SEM.