title: Regulatory effect of the glial Golli-BG21 protein on the full-length murine small C-terminal domain phosphatase (SCP1, or Golli-interacting protein).
abstract: The gene in the oligodendrocyte lineage (golli) encodes a number of proteins essential for myelination, comprising Golli and classic isoforms that are expressed in a developmentally-regulated manner. The Golli-interacting-protein (GIP) was previously discovered in a search for potential interacting partners of the Golli-isoform BG21, and was realised to be an acidic phosphatase belonging to the family of RNA-polymerase-2, small-subunit, C-terminal phosphatases (viz., SCP1). Here, we refer to this protein as mSCP1/GIP. In subsequent in vitro studies of recombinant murine SCP1/GIP, the inability to produce an active full-length version of the protein under native conditions necessitated the study of a truncated form ΔN-rmSCP1/GIP, but with inconclusive results regarding its interaction with BG21 [13]. We have since developed a new SUMO-expression and purification protocol for the preparation of a functional, full-length mGIP/SCP1, with no additional purification tags. Here, the interaction between mSCP1/GIP (with intact N-terminus) and BG21 is shown to be different than for the truncation mutant studied previously. Specifically, this interaction shows a dual effect on the enzymatic activity of mSCP1/GIP by BG21: BG21 enhanced mSCP1/GIP phosphatase activity (Ka = 30 μM), whereas PKCα-phosphorylated BG21 inhibited its activity (Ki = 2.9 μM), suggesting a potential role of BG21 as a molecular switch ("quick-brake mechanism") on mSCP1/GIP. The successful production of an active, full-length mSCP1/GIP thus demonstrates a role for its N-terminus in regulation of phosphatase activity, in events such as the regulation of transcription in oligodendrocytes.
authors.affiliation: Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada.
authors.forename: Sergio
authors.initials: S
authors.lastname: Jaramillo-Tatis
authors.affiliation: Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada.
authors.forename: Kenrick A
authors.initials: KA
authors.lastname: Vassall
authors.affiliation: Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Bamm
authors.affiliation: Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada. Electronic address: gharauz@uoguelph.ca.
authors.forename: George
authors.initials: G
authors.lastname: Harauz
mesh_terms: D000818:Animals; D018507:Gene Expression Regulation, Developmental; D064267:Intrinsically Disordered Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D008954:Models, Biological; D004676:Myelin Basic Protein / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D009836:Oligodendroglia / Q000166:cytology / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D054730:Protein Interaction Domains and Motifs; D051571:Protein Kinase C-alpha / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D064267:Intrinsically Disordered Proteins; C499047:Mbp protein, mouse; D004676:Myelin Basic Protein; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; C483466:golli-interacting protein, mouse; D051571:Protein Kinase C-alpha; D010744:Phosphoric Monoester Hydrolases
keywords: Golli (gene in the oligodendrocyte lineage); Golli-interacting protein; Intrinsically-disordered protein; Myelin basic protein; Oligodendrocyte; Small C-terminal domain phosphatase