Specificity of the STAR/GSG domain protein Qk1: implications for the regulation of myelination.

Inadequate formation and maintenance of myelin is the basis for several neurodegenerative disorders, including leukodystrophy and multiple sclerosis. In mice, oligodendrocyte differentiation and subsequent formation of myelin requires the Quaking gene. Mutation of this gene leads to embryonic lethality or to a trembling phenotype characteristic of dysmyelination. Quaking encodes Qk1, a member of the highly conserved STAR/GSG family of RNA-binding proteins that function as master developmental regulators in higher eukaryotes. Qk1 has been implicated in the regulation of alternative splicing, stability, and translation control of mRNAs that code for myelin structural components in glial cells. We have used quantitative gel mobility shift and fluorescence polarization assays to define the nucleotide sequence specificity of the Qk1 STAR/GSG domain, and to probe the interaction between Qk1 and the 3'-untranslated region (UTR) of myelin basic protein (MBP) mRNA. The results show that Qk1 recognizes a hexanucleotide consensus element that is similar although not identical to the specificity determinant recognized by the Caenorhabditis elegans STAR/GSG protein GLD-1. Several consensus sites are present in the 3'-UTR of MBP mRNA. The highest affinity site is located within the RNA localization region, suggesting a possible role for Qk1 in restricting MBP mRNA to the myelin compartment.

[1]  N. Perrone-Bizzozero,et al.  Role of HuD and other RNA‐binding proteins in neural development and plasticity , 2002, Journal of neuroscience research.

[2]  K. Artzt,et al.  The Quaking I-5 Protein (QKI-5) Has a Novel Nuclear Localization Signal and Shuttles between the Nucleus and the Cytoplasm* , 1999, The Journal of Biological Chemistry.

[3]  E. Barbarese.  Spatial distribution of myelin basic protein mRNA and polypeptide in Quaking oligodendrocytes in culture , 1991, Journal of neuroscience research.

[4]  S. Richard,et al.  Nuclear Retention of MBP mRNAs in the Quaking Viable Mice , 2002, Neuron.

[5]  A. Riggs,et al.  Lac repressor binding to non-operator DNA: detailed studies and a comparison of eequilibrium and rate competition methods. , 1972, Journal of molecular biology.

[6]  T. Schedl,et al.  Identification of in vivo mRNA targets of GLD-1, a maxi-KH motif containing protein required for C. elegans germ cell development. , 2001, Genes & development.

[7]  P. Grabowski,et al.  Function of quaking in myelination: Regulation of alternative splicing , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[8]  Yue Feng,et al.  Destabilization and Mislocalization of Myelin Basic Protein mRNAs in quaking Dysmyelination Lacking the QKI RNA-Binding Proteins , 2000, The Journal of Neuroscience.

[9]  M. Rosbash,et al.  A cooperative interaction between U2AF65 and mBBP/SF1 facilitates branchpoint region recognition. , 1998, Genes & development.

[10]  M. Justice,et al.  Three ENU-induced alleles of the murine quaking locus are recessive embryonic lethal mutations. , 1988, Genetical research.

[11]  E. B. Goodwin,et al.  The STAR protein, GLD‐1, is a translational regulator of sexual identity in Caenorhabditis elegans , 1999, The EMBO journal.

[12]  K. Artzt,et al.  STAR, a gene family involved in signal transduction and activation of RNA. , 1997, Trends in genetics : TIG.

[13]  J. Carson,et al.  Transport and localization of exogenous myelin basic protein mRNA microinjected into oligodendrocytes , 1993, The Journal of cell biology.

[14]  Sean P Ryder,et al.  RNA target specificity of the STAR/GSG domain post-transcriptional regulatory protein GLD-1 , 2004, Nature Structural &Molecular Biology.

[15]  S. Warren,et al.  FMR1 protein: conserved RNP family domains and selective RNA binding. , 1993, Science.

[16]  J. Richter,et al.  Selective translation of mRNAs at synapses , 2002, Current Opinion in Neurobiology.

[17]  S. Richard,et al.  kep1 interacts genetically with dredd/Caspase-8, and kep1 mutants alter the balance of dredd isoforms , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[18]  S. Richard,et al.  Structure-Function Analysis of Qk1: a Lethal Point Mutation in Mouse quaking Prevents Homodimerization , 1998, Molecular and Cellular Biology.

[19]  E. Baehrecke.  who encodes a KH RNA binding protein that functions in muscle development. , 1997, Development.

[20]  R. Sidman,et al.  Mutant Mice (Quaking and Jimpy) with Deficient Myelination in the Central Nervous System , 1964, Science.

[21]  M. Justice,et al.  The quaking gene product necessary in embryogenesis and myelination combines features of RNA binding and signal transduction proteins , 1996, Nature Genetics.

[22]  J. Kamholz,et al.  Alternative splicing accounts for the four forms of myelin basic protein , 1985, Cell.

[23]  V. LeTilly,et al.  Fluorescence anisotropy assays implicate protein-protein interactions in regulating trp repressor DNA binding. , 1993, Biochemistry.

[24]  M. Hammarskjöld,et al.  Sam68 Enhances the Cytoplasmic Utilization of Intron-Containing RNA and Is Functionally Regulated by the Nuclear Kinase Sik/BRK , 2003, Molecular and Cellular Biology.

[25]  K. Mikoshiba,et al.  Structure and function of myelin protein genes. , 1991, Annual review of neuroscience.

[26]  M. Rosbash,et al.  The Splicing Factor BBP Interacts Specifically with the Pre-mRNA Branchpoint Sequence UACUAAC , 1997, Cell.

[27]  J. Carson,et al.  The Cis-Acting RNA Trafficking Signal from Myelin Basic Protein mRNA and Its Cognate Trans-Acting Ligand Hnrnp A2 Enhance CaP-Dependent Translation , 1999, The Journal of cell biology.

[28]  D. Crothers,et al.  RNA binding assays for Tat-derived peptides: implications for specificity. , 1992, Biochemistry.

[29]  The quakingviable mutation affects qkI mRNA expression specifically in myelin-producing cells of the nervous system. , 2003, Nucleic acids research.

[30]  T. C. Evans,et al.  Translational repression of a C. elegans Notch mRNA by the STAR/KH domain protein GLD-1 , 2003, Development.

[31]  R. Hardy.  QKI expression is regulated during neuron‐glial cell fate decisions , 1998, Journal of neuroscience research.

[32]  Daniela Avossa,et al.  Transport and Localization Elements in Myelin Basic Protein mRNA , 1997, The Journal of cell biology.

[33]  R. Hardy.  Molecular defects in the dysmyelinating mutant quaking , 1998, Journal of neuroscience research.

[34]  Ana C. Messias,et al.  Structural Basis for Recognition of the Intron Branch Site RNA by Splicing Factor 1 , 2001, Science.

[35]  J. Henson,et al.  HuD, a paraneoplastic encephalomyelitis antigen, contains RNA-binding domains and is homologous to Elav and sex-lethal , 1991, Cell.

[36]  K. Artzt,et al.  The STAR protein QKI-6 is a translational repressor. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[37]  T. Schedl,et al.  gld-1, a tumor suppressor gene required for oocyte development in Caenorhabditis elegans. , 1995, Genetics.

[38]  Alan D. Frankel,et al.  Recognition of RNA Branch Point Sequences by the KH Domain of Splicing Factor 1 (Mammalian Branch Point Binding Protein) in a Splicing Factor Complex , 2001, Molecular and Cellular Biology.

[39]  K. Artzt,et al.  Neural Cell Type-Specific Expression of QKI Proteins Is Altered in quakingviable Mutant Mice , 1996, The Journal of Neuroscience.