A novel Golgi-associated Vangl2 translational variant required for PCP regulation in vertebrates

First described in Drosophila melanogaster, planar cell polarity (PCP) is a developmental process essential for embryogenesis and development of polarized structures in Metazoans. This signaling pathway involves a set of evolutionarily conserved genes encoding transmembrane (Vangl, Frizzled, Celsr) and cytoplasmic (Prickle, Dishevelled) molecules. Vangl2 is of major importance in embryonic development as illustrated by its pivotal role during neural tube closure in human, mouse, Xenopus and zebrafish embryos. The regulated and poorly understood traffic of Vangl2 to the plasma membrane is a key event for its function in development. Here we report on the molecular and functional characterization of a novel 569-amino acid N-terminally extended Vangl2 isoform, Vangl2-Long, that arises from an alternative non-AUG translation initiation site, lying 144 base pair upstream of the conventional start codon. While missing in Vangl1 paralogs and in all invertebrates, including Drosophila melanogaster, this N-terminal extension is conserved in all vertebrate Vangl2 sequences and confers a subcellular localization in the Golgi apparatus, probably as a result of an extended retention time in this organelle. Vangl2-Long belongs to a multimeric complex with Vangl1 and Vangl2 and we show that its down-regulation leads to severe PCP-related phenotypes in Xenopus embryos, including shorter body axis and neural tube closure defects. Altogether, our study unveils a novel level of complexity in Vangl2 expression, trafficking and function.

[1]  B. Storrie,et al.  Golgi structure formation, function, and post-translational modifications in mammalian cells , 2017, F1000Research.

[2]  J. Borg,et al.  The planar cell polarity Vangl2 protein: From genetics to cellular and molecular functions. , 2017, Seminars in cell & developmental biology.

[3]  J. Wilusz,et al.  Non-AUG translation: a new start for protein synthesis in eukaryotes , 2017, Genes & development.

[4]  John B. Wallingford,et al.  Planar cell polarity in development and disease , 2017, Nature Reviews Molecular Cell Biology.

[5]  H. Strutt,et al.  Robust Asymmetric Localization of Planar Polarity Proteins Is Associated with Organization into Signalosome-like Domains of Variable Stoichiometry , 2016, Cell reports.

[6]  J. Garcia-Fernández,et al.  Evolutionary development of embryonic cerebrospinal fluid composition and regulation: an open research field with implications for brain development and function , 2016, Fluids and Barriers of the CNS.

[7]  Daniel Birnbaum,et al.  Identification of p62/SQSTM1 as a component of non-canonical Wnt VANGL2–JNK signalling in breast cancer , 2016, Nature Communications.

[8]  S. Sokol,et al.  Planar polarization of Vangl2 in the vertebrate neural plate is controlled by Wnt and Myosin II signaling , 2015, Biology Open.

[9]  B. Ciruna,et al.  The clathrin adaptor AP-1 complex and Arf1 regulate planar cell polarity in vivo , 2015, Nature Communications.

[10]  A. Inutsuka,et al.  Vangl2 Regulates E-Cadherin in Epithelial Cells , 2014, Scientific Reports.

[11]  J. Borg,et al.  Insight into planar cell polarity. , 2014, Experimental cell research.

[12]  Xiajuan Zou,et al.  PTENα, a PTEN isoform translated through alternative initiation, regulates mitochondrial function and energy metabolism. , 2014, Cell metabolism.

[13]  W. Van Criekinge,et al.  N-terminal Proteomics and Ribosome Profiling Provide a Comprehensive View of the Alternative Translation Initiation Landscape in Mice and Men* , 2014, Molecular & Cellular Proteomics.

[14]  Jennifer S. Yu,et al.  A Secreted PTEN Phosphatase That Enters Cells to Alter Signaling and Survival , 2013, Science.

[15]  J. Reboul,et al.  The Human PDZome: A Gateway to PSD95-Disc Large-Zonula Occludens (PDZ)-mediated Functions* , 2013, Molecular & Cellular Proteomics.

[16]  J. Tavaré,et al.  A global analysis of SNX27–retromer assembly and cargo specificity reveals a function in glucose and metal ion transport , 2013, Nature Cell Biology.

[17]  R. Schekman,et al.  A novel GTP-binding protein–adaptor protein complex responsible for export of Vangl2 from the trans Golgi network , 2013, eLife.

[18]  J. Reboul,et al.  Gipc1 has a dual role in Vangl2 trafficking and hair bundle integrity in the inner ear , 2012, Development.

[19]  M. Montcouquiol,et al.  Molecular Characterisation of Endogenous Vangl2/Vangl1 Heteromeric Protein Complexes , 2012, PloS one.

[20]  W. Rossmanith.  Localization of Human RNase Z Isoforms: Dual Nuclear/Mitochondrial Targeting of the ELAC2 Gene Product by Alternative Translation Initiation , 2011, PloS one.

[21]  Carlos J. Madrid-Aliste,et al.  A Nuclear Variant of ErbB3 Receptor Tyrosine Kinase Regulates Ezrin Distribution and Schwann Cell Myelination , 2011, The Journal of Neuroscience.

[22]  P. Gros,et al.  Transmembrane topology of mammalian planar cell polarity protein Vangl1. , 2011, Biochemistry.

[23]  Y. Minami,et al.  Wnt signaling gradients establish planar cell polarity by inducing Vangl2 phosphorylation through Ror2. , 2011, Developmental cell.

[24]  P. Gros,et al.  Loss of membrane targeting of Vangl proteins causes neural tube defects. , 2011, Biochemistry.

[25]  Andrew E. Firth,et al.  Identification of evolutionarily conserved non-AUG-initiated N-terminal extensions in human coding sequences , 2011, Nucleic acids research.

[26]  Bai-Lin Wu,et al.  VANGL2 mutations in human cranial neural-tube defects. , 2010, The New England journal of medicine.

[27]  P. Gros,et al.  Molecular and cellular mechanisms underlying neural tube defects in the loop-tail mutant mouse. , 2010, Biochemistry.

[28]  E. Cuppen,et al.  Planar cell polarity defects and defective Vangl2 trafficking in mutants for the COPII gene Sec24b , 2010, Development.

[29]  Randy Schekman,et al.  Sec24b selectively sorts Vangl2 to regulate planar cell polarity during neural tube closure , 2009, Nature Cell Biology.

[30]  R. Kobayashi,et al.  Targeted mass spectrometric analysis of N‐terminally truncated isoforms generated via alternative translation initiation , 2009, FEBS letters.

[31]  E. Fuchs,et al.  Planar Polarization in Embryonic Epidermis Orchestrates Global Asymmetric Morphogenesis of Hair Follicles , 2008, Nature Cell Biology.

[32]  G. Andelfinger,et al.  Genetic interaction between members of the Vangl family causes neural tube defects in mice , 2008, Proceedings of the National Academy of Sciences.

[33]  J. Wallingford,et al.  Mutations in VANGL1 associated with neural-tube defects. , 2007, The New England journal of medicine.

[34]  A. Forge,et al.  Asymmetric Localization of Vangl2 and Fz3 Indicate Novel Mechanisms for Planar Cell Polarity in Mammals , 2006, The Journal of Neuroscience.

[35]  Alexander F. Schier,et al.  Planar cell polarity signalling couples cell division and morphogenesis during neurulation , 2006, Nature.

[36]  P. Gros,et al.  Van Gogh-like2 (Strabismus) and its role in planar cell polarity and convergent extension in vertebrates. , 2004, Trends in Genetics.

[37]  J. Jessen,et al.  Identification and developmental expression pattern of van gogh-like 1, a second zebrafish strabismus homologue. , 2004, Gene expression patterns : GEP.

[38]  Kuang-Jung Chang,et al.  Translation Initiation from a Naturally Occurring Non-AUG Codon in Saccharomyces cerevisiae* , 2004, Journal of Biological Chemistry.

[39]  A. Prats,et al.  Generation of protein isoform diversity by alternative initiation of translation at non‐AUG codons , 2003, Biology of the cell.

[40]  Lilianna Solnica-Krezel,et al.  Zebrafish trilobite identifies new roles for Strabismus in gastrulation and neuronal movements , 2002, Nature Cell Biology.

[41]  Marek Mlodzik,et al.  The planar polarity gene strabismus regulates convergent extension movements in Xenopus , 2002, The EMBO journal.

[42]  N. Hilschmann,et al.  Golgi retention of human protein NEFA is mediated by its N‐terminal Leu/Ile‐rich region , 2001, FEBS letters.

[43]  L. Créancier,et al.  New vascular endothelial growth factor isoform generated by internal ribosome entry site-driven CUG translation initiation. , 2001, Molecular endocrinology.

[44]  A. Copp,et al.  Severe neural tube defects in the loop-tail mouse result from mutation of Lpp1, a novel gene involved in floor plate specification. , 2001, Human molecular genetics.

[45]  M. Justice,et al.  Ltap, a mammalian homolog of Drosophila Strabismus/Van Gogh, is altered in the mouse neural tube mutant Loop-tail , 2001, Nature Genetics.

[46]  J. Ovesná,et al.  Characterization of two bifunctional Arabdopsis thaliana genes coding for mitochondrial and cytosolic forms of valyl-tRNA synthetase and threonyl-tRNA synthetase by alternative use of two in-frame AUGs. , 1999, European journal of biochemistry.

[47]  J. Taylor,et al.  Van Gogh: a new Drosophila tissue polarity gene. , 1998, Genetics.

[48]  G. Rubin,et al.  Strabismus, a novel gene that regulates tissue polarity and cell fate decisions in Drosophila. , 1998, Development.

[49]  G. Peters,et al.  Subcellular fate of the lnt-2 oncoprotein is determined by choice of initiation codon , 1990, Nature.

[50]  J. Ebel,et al.  The yeast VAS1 gene encodes both mitochondrial and cytoplasmic valyl-tRNA synthetases. , 1988, The Journal of biological chemistry.

[51]  F. Hilger,et al.  The HTS1 gene encodes both the cytoplasmic and mitochondrial histidine tRNA synthetases of S. cerevisiae , 1986, Cell.

[52]  P. Gros,et al.  An expanding role of Vangl proteins in embryonic development. , 2012, Current topics in developmental biology.

[53]  Randall T. Moon,et al.  The planar cell-polarity gene stbm regulates cell behaviour and cell fate in vertebrate embryos , 2002, Nature Cell Biology.