title: Identification of Lck-binding elements in tip of herpesvirus saimiri.
abstract: A protein called Tip (tyrosine kinase interacting protein) of herpesvirus saimiri associates with Lck in virus-transformed human T cells and is an in vitro substrate for Lck kinase. Mutational analyses of a GST-Tip fusion protein revealed that binding to Lck requires putative SH3 binding sequences and a sequence homologous to the carboxyl terminus of Src-related kinases. These sequences are referred to as SH3-Binding (SH3B) and C-terminal Src-related Kinase Homology (CSKH) elements. Peptide fragments as short as 37 amino acids containing both SH3B and CSKH elements were sufficient to form a stable complex with Lck in vitro. Furthermore, these same sequences of Tip were necessary for in vivo association with Lck when Tip and Lck were expressed transiently in COS-1 cells or stably in Rat-1 cell lines. These results demonstrate that the CSKH element of Tip participates in the binding of sequences within Lck. Tip of herpesvirus saimiri has apparently acquired such CSKH and SH3B elements for the purpose of targeting cellular protein kinases. The interaction of Tip with Lck may influence Lck kinase activity or its binding to other cellular proteins and thereby alter Lck function in T cells infected by h. saimiri.
authors.affiliation: Department of Microbiology and Molecular Genetics, New England Regional Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102, USA.
authors.forename: J U
authors.initials: JU
authors.lastname: Jung
authors.forename: S M
authors.initials: SM
authors.lastname: Lang
authors.forename: U
authors.initials: U
authors.lastname: Friedrich
authors.forename: T
authors.initials: T
authors.lastname: Jun
authors.forename: T M
authors.initials: TM
authors.lastname: Roberts
authors.forename: R C
authors.initials: RC
authors.lastname: Desrosiers
authors.forename: B
authors.initials: B
authors.lastname: Biesinger
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002522:Chlorocebus aethiops; D017931:DNA Primers; D006567:Herpesvirus 2, Saimiriine / Q000378:metabolism*; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism*; D010768:Phosphoserine / Q000032:analysis; D010769:Phosphothreonine / Q000032:analysis; D019000:Phosphotyrosine; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D018411:Spodoptera; D013329:Structure-Activity Relationship; D014162:Transfection; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis; D014764:Viral Proteins / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D010446:Peptide Fragments; D010750:Phosphoproteins; D011994:Recombinant Proteins; D014764:Viral Proteins; C092384:tyrosine kinase interacting protein, Saimiriine herpesvirus 2; D010769:Phosphothreonine; D010768:Phosphoserine; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck)