title: Determinants of the interaction of the spinal muscular atrophy disease protein SMN with the dimethylarginine-modified box H/ACA small nucleolar ribonucleoprotein GAR1.
abstract: Deletion or mutation of the SMN1 (survival of motor neurons) gene causes the common, fatal neuromuscular disease spinal muscular atrophy. The SMN protein is important in small nuclear ribonucleoprotein (snRNP) assembly and interacts with snRNP proteins via arginine/glycine-rich domains. Recently, SMN was also found to interact with core protein components of the two major families of small nucleolar RNPs, fibrillarin and GAR1, suggesting that SMN may also function in the assembly of small nucleolar RNPs. Here we present results that indicate that the interaction of SMN with GAR1 is mediated by the Tudor domain of SMN. Single point mutations within the Tudor domain, including a spinal muscular atrophy patient mutation, impair the interaction of SMN with GAR1. Furthermore, we find that either of the two arginine/glycine-rich domains of GAR1 can provide for interaction with SMN, but removal of both results in loss of the interaction. Finally, we have found that unlike the interaction of SMN with the Sm snRNP proteins, interaction with GAR1 and fibrillarin is not enhanced by arginine dimethylation. Our results argue against post-translational arginine dimethylation as a general requirement for SMN recognition of proteins bearing arginine/glycine-rich domains.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Georgia, Athens 30602, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Whitehead
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Jones
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Cheng
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Terns
authors.forename: Michael P
authors.initials: MP
authors.lastname: Terns
mesh_terms: D019943:Amino Acid Substitution; D001120:Arginine / Q000378:metabolism; D001483:Base Sequence; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein; D017931:DNA Primers; D005656:Fungal Proteins / Q000378:metabolism*; D008745:Methylation; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D017354:Point Mutation; D011485:Protein Binding; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020718:Ribonucleoproteins, Small Nucleolar; D055532:SMN Complex Proteins; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D017362:Cyclic AMP Response Element-Binding Protein; D017931:DNA Primers; D005656:Fungal Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D020718:Ribonucleoproteins, Small Nucleolar; D055532:SMN Complex Proteins; D029701:Saccharomyces cerevisiae Proteins; C047458:fibrillarin; C073180:GAR1 protein, S cerevisiae; D001120:Arginine