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Biology subjects

Klostermann, M.

Publications and source records attributed to Klostermann, M..

2 recordsLinked to original sources

Depletion of the RNA-binding protein PURA triggers changes in posttranscriptional gene regulation and loss of P-bodies

The RNA-binding protein PURA has been implicated in the rare, monogenetic, neurodevelopmental disorder PURA Syndrome. PURA binds both DNA and RNA and has been associated with various cellular functions. Only little is known about its main cellular roles and the molecular pathways affected upon PURA depletion. Here, we show that PURA is predominantly located in the cytoplasm, where it binds to thousands of mRNAs. Many of these transcripts change abundance in response to PURA depletion. The encoded proteins suggest a role for PURA in immune responses, mitochondrial function, autophagy and processing (P)-body activity. Intriguingly, reduced PURA levels decrease the expression of the integral P-body components LSM14A and DDX6 and strongly affect P-body formation in human cells. Furthermore, PURA knockdown results in stabilization of P-body-enriched transcripts, whereas other mRNAs decrease. Hence, reduced PURA levels, as reported in patients with PURA Syndrome, influence the formation and composition of this phase-separated RNA processing machinery. Our study proposes PURA Syndrome as a new model to study the tight connection between P-body-associated RNA regulation and neurodevelopmental disorders. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/479353v2_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@5712f9org.highwire.dtl.DTLVardef@9eb133org.highwire.dtl.DTLVardef@83b7b2org.highwire.dtl.DTLVardef@1912e5c_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

Modulation of pre-mRNA structure by hnRNP proteins regulates alternative splicing of MALT1

Alternative splicing is controlled by differential binding of trans-acting RNA binding proteins (RBPs) to cis-regulatory elements in intronic and exonic pre-mRNA regions 1-3. How secondary structure in the pre-mRNA transcripts affects recognition by RBPs and determines alternative exon usage is poorly understood. The MALT1 paracaspase is a key component of signaling pathways that mediate innate and adaptive immune responses 4. Alternative splicing of MALT1 exon7 is critical for controlling optimal T cell activation 5,6. Here, we demonstrate that processing of the MALT1 pre-mRNA depends on RNA structural elements that shield the 5 and 3 splice sites of the alternatively spliced exon7. By combining biochemical analyses with chemical probing and NMR we show that the RBPs hnRNP U and hnRNP L bind competitively and with comparable affinities to identical stem-loop RNA structures flanking the 5 and 3 splice sites of MALT1 exon7. While hnRNP U stabilizes RNA stem-loop conformations that maintain exon7 skipping, hnRNP L unwinds these RNA elements to facilitate recruitment of the essential splicing factor U2AF2 to promote exon7 inclusion. Our data represent a paradigm for the control of splice site selection by differential RBP binding and modulation of pre-mRNA structure.

biochemistry↗