Fornerod Lab - The Netherlands Cancer Institute

<head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta http-equiv="Content-Language" content="en-us"> <title>Fornerod Lab - The Netherlands Cancer Institute</title> <meta name="GENERATOR" content="Microsoft FrontPage 4.0"> </head> <body bgcolor="#94d6e7" text="#000000" link="#110978" vlink="#B40121" alink="#B40121"> <font face="Verdana" size="5" color="#2101B4">Fornerod Lab</font> <p style="line-height: 200%"> <font face="Verdana" size="2"> <nobr><a href="http://research.nki.nl/fornerodlab" target="_blank">Main</a></nobr><br><nobr><a href="Main.html#members" target="Content">Lab members</a></nobr><br> <nobr><a href="main.html#projects" target="Content">Current projects</a></nobr><br> <nobr><a href="Publications.htm" target="Content">Publications</a></nobr><br> <nobr><a href="Past-research.html" target="Content">Past research</a></nobr><br> <nobr><a href="Main.html#jobs" target="Content">Job/internship opportunities</a></nobr><br> <nobr><a href="Rejected-cover-art.htm" target="Content">Rejected Cover Art</a></nobr><br> <nobr><a href="NES-Finder.htm" target="Content">NO WARRENTY: NES Finder 0.2</a></nobr><br> <nobr><a href="Main.html#jobs" target="Content">Contact</a></nobr><br> <nobr><a href="Social.htm" target="Content">Social affairs</a></nobr><br> <a href="http://www.nki.nl" rel=nofollow target="_blank">NKI home</a></font> <center> <font face="Verdana" size="5" color="#2101B4"> Dynamic interactions at the nuclear envelope</font> <p> <img border="0" src="Tulip.jpg" width="330" height="330"> <p> <table border="0" width="90%" style="font-family: Verdana; font-size: 10pt; margin-left: 15"> <tr> <td><font face="Verdana" size="3"><font face="Verdana"><font size="2"><span style="font-family: Verdana; mso-bidi-font-weight: normal; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: Times; mso-bidi-font-family: Times New Roman; color: black; mso-ansi-language: NL; mso-fareast-language: EN-US; mso-bidi-language: AR-SA" lang="NL"> The nuclear envelope arguably is the most important border within the eukaryotic cell. Borders in general are stable, but can reflect the dynamics of an entire organization. This makes them an attractive platform from which to study a complex system -- such as the eukaryotic cell.</font></span></font><p><br><p></td> </tr> </table> <center> <font face="Verdana" size="5" color="#2101B4"> <A NAME="members"></A>Current lab members</font> <table border="0" width="50%"> <tr> <td width="30%"><img border="0" src="Hella.jpg" align="center"> <td width="30%"><img border="0" src="stijn_s.jpg"> <td width="30%"><img border="0" src="nikos.jpg"> </tr> <tr> <td width="30%"><img border="0" src="Dieuwke.jpg" align="center"> <td width="30%"><img border="0" src="Bernike.jpg"> <td width="30%"><img border="0" src="Michael_s.jpg"> </tr> <td width="30%"><img border="0" src="mf.jpg" align="center"> </tr> </table> <center> <table border="0" width="80%" style="font-family: Verdana; font-size: 10pt; margin-left: 15"> <tr> <td><font face="Verdana" size="3"><br><font face="Verdana"><font size="2"><span style="font-family: Verdana; mso-bidi-font-weight: normal; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: Times; mso-bidi-font-family: Times New Roman; color: black; mso-ansi-language: NL; mso-fareast-language: EN-US; mso-bidi-language: AR-SA" lang="NL"> Left to right: <a href="mailto:h.vd.velde@nki.nl">Hella van der Velde</a>, Research technician; <a href="mailto:s.heessen@nki.nl">Stijn Heessen</a>, Post-doctoral fellow, <a href="mailto:n.xylourgidis@nki.nl">Nikos Xylourgidis</a>, Post-doctoral fellow, <a href="mailto:d.engelsma@nki.nl">Dieuwke Engelsma</a>, Ph.D. student, <a href="mailto:b.kalverda@nki.nl"">Bernike Kalverda</a>, Ph.D. student, <a href="mailto:Michael.Roling@student.uva.nl">Michael Röling</a>, undergraduate student, <a href="mailto:m.fornerod@nki.nl">Maarten Fornerod</a>, Group leader.</font></span></font><p><br><p></td> </tr> </table> <center> <font face="Verdana" size="5" color="#2101B4"> Past lab members</font> <table border="0" width="30%"> <tr> <td width="30%"><img border="0" src="Helen.jpg" align="center"> <td width="30%"><img border="0" src="Rafa.jpg"> <td width="30%"><img border="0" src="jolita.jpg"> </tr> </table> <table border="0" width="80%" style="font-family: Verdana; font-size: 10pt; margin-left: 15"> <tr> <td><font face="Verdana" size="3"><br><font face="Verdana"><font size="2"><span style="font-family: Verdana; mso-bidi-font-weight: normal; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: Times; mso-bidi-font-family: Times New Roman; color: black; mso-ansi-language: NL; mso-fareast-language: EN-US; mso-bidi-language: AR-SA" lang="NL"> Left to right: Helen Pickersgill, Postdoctoral Fellow. Currently: editor Developmental Cell, Boston, USA; Rafael Bernad, Ph.D. student. Currently: Post-doctoral fellow, CNIO, Madrid, Spain; Jolita Hendriksen, Ph.D. Student; not shown: Noelia Valle, short term EMBO fellow; Marnix Jansen, guest student. </font></span><p></td> </tr> </table> <center> <font face="Verdana" size="5" color="#2101B4"><br> <a name="projects">Current projects</a></font> <br> <p> <HR NOSHADE SIZE=3 WIDTH="70%"> <p> <center><img border="0" src="S1-GFP.jpg" hight=150, width=150> </center> <font face="Verdana"><b><font face="Verdana" size="2"><br> Nuclear export signals: Born to be weak</font></font></b><br> <table border="0" width="80%" style="font-family: Verdana; font-size: 10pt; margin-left: 15"> <tr> <td><font face="Verdana" size="3"><br><font face="Verdana"><font size="2"><span style="font-family: Verdana; mso-bidi-font-weight: normal; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: Times; mso-bidi-font-family: Times New Roman; color: black; mso-ansi-language: NL; mso-fareast-language: EN-US; mso-bidi-language: AR-SA" lang="NL"> Leucine-rich nuclear export signals (NESs) mediate rapid nuclear export of proteins via interaction with CRM1. Although this interaction is stimulated by RanGTP, it remains of a relatively low affinity. For this reason NESs are difficult to detect biochemically. NESs are difficult to predict as well. as the consensus sequence is very loose. In other words: NESs are a pain. But why?<p> To answer this, we screened a 15-mer random peptide library for CRM1 binding in order to identify strong signals. In this way we identified NESs with a very high affinity for CRM1 in vitro. In fact, the affinity is so high that they stably bind without the requirement of RanGTP. We have dubbed these signals "supraphysiological" NESs, or superNESs for short.<p> SuperNESs behave peculiarly in vivo: they are inefficient in mediating nuclear export and instead accumulate together with CRM1 at nucleoporin Nup358. From this we conclude that NESs have evolved to maintain low affinity for CRM1; allowing efficient export complex disassembly and release from Nup358. These results stress the importance of weak, almost invisible interactions -- that are a pain to work with. <p> <a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15752974&query_hl=4" rel=nofollow target="_Blank">Read more: Nuclear export signals: Born to be weak. Trends in Cell Biology, 2005.</a> </font></span><p><br><p></td> </tr> </table> <HR NOSHADE SIZE=3 WIDTH="70%"><p> <center><img border="0" src="Drosophila_cel_EM_web.jpg" hight=200, width=200> </center><p> <font face="Verdana"><b><font face="Verdana" size="2"><br> Nuclear envelope chromatin interactions: From the inside looking in</font></font></b><br> <table border="0" width="80%" style="font-family: Verdana; font-size: 10pt; margin-left: 15"> <tr> <td><font face="Verdana" size="3"><br><font face="Verdana"><font size="2"><span style="font-family: Verdana; mso-bidi-font-weight: normal; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: Times; mso-bidi-font-family: Times New Roman; color: black; mso-ansi-language: NL; mso-fareast-language: EN-US; mso-bidi-language: AR-SA" lang="NL"> Many observations suggest that the nuclear envelope plays a key role in the spatial and functional organization of chromatin. In close collaboration with the lab of Bas van Steensel (Dept. of Molecular Genetics), we are analyzing the behaviour of genes in respect to various nuclear envelope components. <p> The nuclear lamina (NL) has long been thought to be an anchoring site of chromatin and to participate in the regulation of gene expression, but genomic sequences that interact with the NL in vivo have remained unknown. We used a genome-wide approach to identify nearly 500 Drosophila genes that interact in vivo with the NL component Lam, a B-type lamin. <p> These genes are transcriptionally silent, late replicating, lack active histone marks, and are widely spaced. These factors collectively predict Lamin binding behavior, indicating the NL integrates variant and invariant chromatin features. Consistently, NE proximity is partly conserved between cell types and induction of gene expression or active histone marks reduces Lam binding. Lam target genes cluster in the genome, and these clusters are coordinately expressed during development. This genome-wide analysis gives clear insight into the nature and dynamic behavior of the genome at the NL and implies that intergenic or "junk" DNA functions in the global organization of chromatin in the nucleus. <p> <a href="Het_nut_van_junk.pdf" target="_Blank">Read more (in Dutch): Het Nut van Junk. NRC Handelsblad, 12-13 augustus 2006.</a> <p> </font></span><p><br><p></td> </tr> </table> <HR NOSHADE SIZE=3 WIDTH="70%"> <p> <center><img border="0" src="grail.jpg" hight=200, width=200> </center><p> <font face="Verdana"><b><font face="Verdana" size="2"><br> Searching for a holy grail: Nuclear export of β-Catenin</font></font></b><br> <table border="0" width="80%" style="font-family: Verdana; font-size: 10pt; margin-left: 15"> <tr> <td><font face="Verdana" size="3"><br><font face="Verdana"><font size="2"><span style="font-family: Verdana; mso-bidi-font-weight: normal; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: Times; mso-bidi-font-family: Times New Roman; color: black; mso-ansi-language: NL; mso-fareast-language: EN-US; mso-bidi-language: AR-SA" lang="NL"> β-Catenin is the nuclear effector of the Wnt signaling cascade. The mechanism by which nuclear activity of β-Catenin is regulated is not very well defined. We identified a cofactor of CRM1-mediated nuclear export, Ran-binding protein 3 (RanBP3) as a novel β-Catenin interacting protein that binds directly to β-Catenin in a RanGTP stimulated manner. <p> In vivo, RanBP3 inhibits β-Catenin-mediated transcriptional activation both in Wnt1 or β-Catenin stimulated human cells. In Xenopus embryos, RanBP3 interferes with β-Catenin-induced dorsoventral axis formation. Furthermore, RanBP3 depletion stimulates the Wnt pathway, both in human cells and Drosophila embryos. In human cells, this is accompanied by an increase of active β-Catenin in the nucleus. Conversely, overexpression of RanBP3 leads to a shift of active β-Catenin towards the cytoplasm. <p> Interestingly, RanBP3 only acts on a very small dephosphorylated nuclear fraction of total β-Catenin, that correlates with transcriptional activity. We can visualize this fraction only in certain colon carcinoma cells that contain "massive" amounts of this active β-Catenin; still only a very small fraction of total β-Catenin. We find that modulation of β-Catenin activity and localization by RanBP3 is independent of APC and CRM1. <p> We conclude that RanBP3 is a direct export enhancer for β-Catenin, independent of its role as a CRM1 associated nuclear export cofactor, and ask -- what is active β-Catenin?<p> <a href="http://www.jcb.org/cgi/content/abstract/171/5/761" rel=nofollow target="_Blank">Read more: Terminating Wnt signals: a novel nuclear export mechanism targets activated β-Catenin. Journal of Cell Biology, 2005</a> </font></span><p><br><p></td> </tr> </table> <HR NOSHADE SIZE=3 WIDTH="70%"> <p> <center><img border="0" src="pickersgill.jpg" hight=300, width=300> </center><p> <font face="Verdana"><b><font face="Verdana" size="2"><br> The closer you look the less you see: structure-function of the nuclear pore complex</font></font></b><br> <table border="0" width="80%" style="font-family: Verdana; font-size: 10pt; margin-left: 15"> <tr> <td><font face="Verdana" size="3"><br><font face="Verdana"><font size="2"><span style="font-family: Verdana; mso-bidi-font-weight: normal; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: Times; mso-bidi-font-family: Times New Roman; color: black; mso-ansi-language: NL; mso-fareast-language: EN-US; mso-bidi-language: AR-SA" lang="NL"> Thanks to the genius and hard work of numerous labs over the last decade, we know almost everything about the structure and function of the nuclear pore complex -- or do we? In any case we've learned quite a bit of what it's not.<p> <p> Our lab has contributed to the "negative knowledge" by providing evidence that the cytoplasmic filaments of the NPC are not required for selective nuclear import, which had been hypothesized previously. Instead, the lab has provided evidence that the cytoplasmic filaments play a supportive role in disassembly of nuclear export complexes. <p> In addition we have identified Nup358 as the main consituent of the cytoplasmic filaments of the NPC, which is anchored to the "core NPC by Nup88. <p> The current focus includes the question which nucleoporins are involved in nuclear export, and whether different types of cargo have different requirements. <p> <p> <a href="http://www.jcb.org/cgi/content/full/158/1/8" rel=nofollow target="_Blank">Read more: The needs of the pore. Journal of Cell Biology, 2002</a> </font></span><p><br><p></td> </tr> </table> <p> <HR NOSHADE SIZE=3 WIDTH="70%"> <p> <p> <center> <font face="Verdana" size="5" color="#2101B4"><br> <a name="jobs">Research opportunities</a></font> <table border="0" width="80%" style="font-family: Verdana; font-size: 10pt; margin-left: 15"> <tr> <td><font face="Verdana" size="3"><br><font face="Verdana"><font size="2"><span style="font-family: Verdana; mso-bidi-font-weight: normal; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: Times; mso-bidi-font-family: Times New Roman; color: black; mso-ansi-language: NL; mso-fareast-language: EN-US; mso-bidi-language: AR-SA" lang="NL"> <center>Please inquire </font></span><p><br><p></td> </tr> </table> <HR NOSHADE SIZE=3 WIDTH="70%"> <p> <center> <font face="Verdana" size="5" color="#2101B4"><br> <a name="contact">Contact</a></font><br> <table border="0" width="80%" style="font-family: Verdana; font-size: 10pt; margin-left: 15"> <tr> <td><font face="Verdana" size="3"><br><font face="Verdana"><font size="2"><span style="font-family: Verdana; mso-bidi-font-weight: normal; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: Times; mso-bidi-font-family: Times New Roman; color: black; mso-ansi-language: NL; mso-fareast-language: EN-US; mso-bidi-language: AR-SA" lang="NL"> <center>Maarten Fornerod <a href="mailto:m.fornerod@nki.nl">m.fornerod@nki.nl</a> <p> Dept of Tumor Biology / H4 <p> Netherlands Cancer Institute <p> Room 416 / Lab 419 <p> Plesmanlaan 121 - 1066 CX Amsterdam, The Netherlands <p> Tel: +31-(0)20-512 2024 </font></span><p><br><p></td> </tr> </table> <table WIDTH="100%" BGCOLOR="#94d6e7" > <tr> <td BGCOLOR="#94d6e7"> <center><a href="http://research.nki.nl/fornerodlab" target="_blank">Main</a></center> </td> </tr> </table> </body>