title: A novel src homology 3 domain-containing adaptor protein, HIP-55, that interacts with hematopoietic progenitor kinase 1.
abstract: Hematopoietic progenitor kinase 1 (HPK1) is a member of the mitogen-activated protein kinase kinase kinase kinase (MAP4K) family and an upstream activator of the c-Jun N-terminal kinase (JNK) signaling cascade. HPK1 interacts, through its proline-rich domains, with growth factor receptor-bound 2 (Grb2), CT10-regulated kinase (Crk), and Crk-like (CrkL) adaptor proteins. We identified a novel HPK1-interacting protein of 55 kDa (HIP-55), similar to the mouse SH3P7 protein, containing an N-terminal actin-binding domain and a C-terminal Src homology 3 domain. We found that HPK1 bound to HIP-55 both in vitro and in vivo. When co-transfected, HIP-55 increased HPK1's kinase activity as well as JNK1's kinase activity. A dominant-negative HPK1 mutant blocked activation of JNK1 by HIP-55 showing that HIP-55 activates the JNK1 signaling pathway via HPK1. Our results identify a novel protein, HIP-55, that binds to HPK1 and regulates the JNK1 signaling cascade.
authors.affiliation: Department of Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: D
authors.initials: D
authors.lastname: Ensenat
authors.forename: Z
authors.initials: Z
authors.lastname: Yao
authors.forename: X S
authors.initials: XS
authors.lastname: Wang
authors.forename: R
authors.initials: R
authors.lastname: Kori
authors.forename: G
authors.initials: G
authors.lastname: Zhou
authors.forename: S C
authors.initials: SC
authors.lastname: Lee
authors.forename: T H
authors.initials: TH
authors.lastname: Tan
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004789:Enzyme Activation; D005260:Female; D015870:Gene Expression; D018922:HL-60 Cells; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D048031:JNK Mitogen-Activated Protein Kinases; D008297:Male; D008840:Microfilament Proteins; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D011392:Proline / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D020798:Two-Hybrid System Techniques; D018909:src Homology Domains / Q000235:genetics*
chemical_list: D002352:Carrier Proteins; C117063:DBNL protein, human; D018076:DNA, Complementary; D008840:Microfilament Proteins; D011993:Recombinant Fusion Proteins; D011392:Proline; C102102:hematopoietic progenitor kinase 1; D017346:Protein Serine-Threonine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases