Linked Life Data

9849903

Source:http://linkedlifedata.com/resource/pubmed/id/9849903

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1998-12-23
pubmed:abstractText
The skeletal muscle glycogen-binding subunit (GM) of protein phosphatase-1 (PP1) is the founding member of a family of proteins that tether the PP1 catalytic subunit (PP1C) to glycogen and promote the dephosphorylation of glycogen synthase. A hydrophobic sequence (called here the VFV motif) is conserved among GM, the liver subunit GL, and the widely expressed subunits, PTG, R5 and U5. This study analyzed the role of this VFV motif in binding to glycogen and PP1C. Glutathione S-transferase (GST) fusions with the N-terminal domain of GM (GST-GM(1-240)) and with the full length R5 protein (GST-R5) both bound to glycogen in a co-sedimentation assay. In contrast, GST itself did not bind to glycogen. A single residue substitution in GST-GM(1-240), F155A, reduced glycogen binding by 40%. Double residue substitutions V150A/F155A and F155A/V159A resulted in greater reductions (60-70%) in glycogen binding, showing these hydrophobic residues influenced the protein-glycogen interaction. The wild type and V150A/ F155A fusion proteins were digested by trypsin into the same sized fragments at the same rate. Furthermore, the wild type and mutated GST-GM proteins as well as GST-R5 bound equivalent amounts of PP1C, in either pull-down or far-Western assays. These results demonstrated retention of overall tertiary structure by the mutated fusion proteins, and indicated that glycogen and PP1C binding are independent of one another. A 68 residue segment of R5 encompassing the VFV motif was sufficient to produce glycogen binding when fused to GST. This motif, that is in bacterial and fungal starch metabolizing enzymes, probably has been conserved during evolution as a functional domain for binding glycogen and starch.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
439
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
185-91
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
A conserved domain for glycogen binding in protein phosphatase-1 targeting subunits.
pubmed:affiliation
Center for Cell Signaling, University of Virginia, Health Sciences Center, Charlottesville 22908, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't