PDBsum entry 1kbe

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Signaling protein PDB id
Protein chain
49 a.a. *
_ZN ×2
* Residue conservation analysis
PDB id:
Name: Signaling protein
Title: Solution structure of the cysteine-rich c1 domain of kinase suppressor of ras
Structure: Kinase suppressor of ras. Chain: a. Fragment: cysteine-rich c1 domain (residues 330-378). Engineered: yes
Source: Mus musculus. House mouse. Organism_taxid: 10090. Gene: ksr1. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.
NMR struc: 1 models
Authors: M.Zhou,D.A.Horita,D.S.Waugh,R.A.Byrd,D.K.Morrison
Key ref:
M.Zhou et al. (2002). Solution structure and functional analysis of the cysteine-rich C1 domain of kinase suppressor of Ras (KSR). J Mol Biol, 315, 435-446. PubMed id: 11786023 DOI: 10.1006/jmbi.2001.5263
06-Nov-01     Release date:   23-Jan-02    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
Q61097  (KSR1_MOUSE) -  Kinase suppressor of Ras 1
873 a.a.
49 a.a.*
Key:    PfamA domain  PfamB domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     intracellular signal transduction   1 term 


DOI no: 10.1006/jmbi.2001.5263 J Mol Biol 315:435-446 (2002)
PubMed id: 11786023  
Solution structure and functional analysis of the cysteine-rich C1 domain of kinase suppressor of Ras (KSR).
M.Zhou, D.A.Horita, D.S.Waugh, R.A.Byrd, D.K.Morrison.
Kinase suppressor of Ras (KSR) is a conserved component of the Ras pathway that acts as a molecular scaffold to promote signal transmission from Raf-1 to MEK and MAPK. All KSR proteins contain a conserved cysteine-rich C1 domain, and studies have implicated this domain in the regulation of KSR1 subcellular localization and function. To further elucidate the biological role of the KSR1 C1 domain, we have determined its three-dimensional solution structure using nuclear magnetic resonance (NMR). We find that while the overall topology of the KSR1 C1 domain is similar to the C1 domains of Raf-1 and PKCgamma, the predicted ligand-binding region and the surface charge distribution are unique. Moreover, by generating chimeric proteins in which these domains have been swapped, we find that the C1 domains of Raf-1, PKCgamma, and KSR1 are not functionally interchangeable. The KSR1 C1 domain does not bind with high affinity or respond biologically to phorbol esters or ceramide, and it does not interact directly with Ras, indicating that the putative ligand(s) for the KSR1 C1 domain are distinct from those that interact with PKCgamma and Raf-1. In addition, our analysis of the chimeric proteins supports the model that Raf-1 is a ceramide-activated kinase and that its C1 domain is involved in the ceramide-mediated response. Finally, our findings demonstrate an absolute requirement of the KSR1 C1 domain in mediating the membrane localization of KSR1, a crucial feature of its scaffolding activity. Together, these results underscore the functional specificity of these important regulatory domains and demonstrate that the structural features of the C1 domains can provide valuable insight into their ligand-binding properties.
  Selected figure(s)  
Figure 2.
Figure 2. Comparison of the KSR1, Raf-1, and PKCg C1 domains. (a) Protein backbone superposition of 11 lowest-energy structures of the KSR1 C1 (residues 331-378), Raf-1 C1 (residues 136-187;[14] Protein Data Bank accession code 1FAQ), and PKCg C1b domains (residues 100-153; [15] Protein Data Bank accession code 1TBO). The flexible regions containing residues with large RMSD values are colored in white. The two Zn ions coordinated in the KSR1 C1 domain are depicted as yellow spheres. (b) Ribbon diagram of the KSR1, Raf-1 (Protein Data Bank accession code 1FAR), and PKCg C1b (Protein Data Bank accession code 1TBN) domains. Arrows indicate the loops predicted to be involved in ligand binding. (c) Amino acid sequences of the KSR1, Raf-1, and PKCg C1b domains. The conserved cysteine and histidine residues that coordinate the Zn ions are shown in red.
Figure 3.
Figure 3. Comparison of the predicted ligand binding regions of the atypical KSR1 (a) and Raf-1 (b) C1 domains. Ribbon diagrams are depicted on the left with the side-chains of hydrophobic residues shown in magenta and the side-chains of hydrophilic residues shown in green. Surface charge diagrams are shown on the right with positive charges in blue, negative charges in red, and neutral charges in white. The diagrams were generated by MOLMOL[51]. A red arrow indicates the positively charged lysine residue found in the b1-b2 loop of the Raf-1 C1 domains and black arrows indicate the Ras-binding site of the Raf-1 C1 domain. and the predicted ligand-binding region of the KSR1 C1 domain.
  The above figures are reprinted by permission from Elsevier: J Mol Biol (2002, 315, 435-446) copyright 2002.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
20820846 C.M.Udell, T.Rajakulendran, F.Sicheri, and M.Therrien (2011).
Mechanistic principles of RAF kinase signaling.
  Cell Mol Life Sci, 68, 553-565.  
21419781 M.D.Stewart, B.Morgan, F.Massi, and T.I.Igumenova (2011).
Probing the determinants of diacylglycerol binding affinity in the C1B domain of protein kinase Cα.
  J Mol Biol, 408, 949-970.  
21458265 M.M.McKay, D.A.Ritt, and D.K.Morrison (2011).
RAF inhibitor-induced KSR1/B-RAF binding and its effects on ERK cascade signaling.
  Curr Biol, 21, 563-568.  
20032303 J.R.Haling, F.Wang, and M.H.Ginsberg (2010).
Phosphoprotein enriched in astrocytes 15 kDa (PEA-15) reprograms growth factor signaling by inhibiting threonine phosphorylation of fibroblast receptor substrate 2alpha.
  Mol Biol Cell, 21, 664-673.  
19139278 E.Giurisato, J.Lin, A.Harding, E.Cerutti, M.Cella, R.E.Lewis, M.Colonna, and A.S.Shaw (2009).
The mitogen-activated protein kinase scaffold KSR1 is required for recruitment of extracellular signal-regulated kinase to the immunological synapse.
  Mol Cell Biol, 29, 1554-1564.  
19710537 X.Yin, M.Zafrullah, H.Lee, A.Haimovitz-Friedman, Z.Fuks, and R.Kolesnick (2009).
A ceramide-binding C1 domain mediates kinase suppressor of ras membrane translocation.
  Cell Physiol Biochem, 24, 219-230.  
18620858 A.S.Harding, and J.F.Hancock (2008).
Using plasma membrane nanoclusters to build better signaling circuits.
  Trends Cell Biol, 18, 364-371.  
18952605 C.A.Kraft, J.L.Garrido, E.Fluharty, L.Leiva-Vega, and G.Romero (2008).
Role of Phosphatidic Acid in the Coupling of the ERK Cascade.
  J Biol Chem, 283, 36636-36645.  
18426801 L.R.Jagemann, L.G.Pérez-Rivas, E.J.Ruiz, J.A.Ranea, F.Sánchez-Jiménez, A.R.Nebreda, E.Alba, and J.Lozano (2008).
The functional interaction of 14-3-3 proteins with the ERK1/2 scaffold KSR1 occurs in an isoform-specific manner.
  J Biol Chem, 283, 17450-17462.  
18266954 P.V.Escribá, J.M.González-Ros, F.M.Goñi, P.K.Kinnunen, L.Vigh, L.Sánchez-Magraner, A.M.Fernández, X.Busquets, I.Horváth, and G.Barceló-Coblijn (2008).
Membranes: a meeting point for lipids, proteins and therapies.
  J Cell Mol Med, 12, 829-875.  
17496912 A.Clapéron, and M.Therrien (2007).
KSR and CNK: two scaffolds regulating RAS-mediated RAF activation.
  Oncogene, 26, 3143-3158.  
17174095 D.A.Ritt, M.Zhou, T.P.Conrads, T.D.Veenstra, T.D.Copeland, and D.K.Morrison (2007).
CK2 Is a component of the KSR1 scaffold complex that contributes to Raf kinase activation.
  Curr Biol, 17, 179-184.  
17071619 D.R.Dries, L.L.Gallegos, and A.C.Newton (2007).
A single residue in the C1 domain sensitizes novel protein kinase C isoforms to cellular diacylglycerol production.
  J Biol Chem, 282, 826-830.  
17496910 M.M.McKay, and D.K.Morrison (2007).
Integrating signals from RTKs to ERK/MAPK.
  Oncogene, 26, 3113-3121.  
17308302 T.E.Fox, K.L.Houck, S.M.O'Neill, M.Nagarajan, T.C.Stover, P.T.Pomianowski, O.Unal, J.K.Yun, S.J.Naides, and M.Kester (2007).
Ceramide recruits and activates protein kinase C zeta (PKC zeta) within structured membrane microdomains.
  J Biol Chem, 282, 12450-12457.  
16551266 A.Mor, and M.R.Philips (2006).
Compartmentalized Ras/MAPK signaling.
  Annu Rev Immunol, 24, 771-800.  
16314390 S.E.Robertson, S.R.Setty, A.Sitaram, M.S.Marks, R.E.Lewis, and M.M.Chou (2006).
Extracellular signal-regulated kinase regulates clathrin-independent endosomal trafficking.
  Mol Biol Cell, 17, 645-657.  
16950780 Y.Pu, M.L.Peach, S.H.Garfield, S.Wincovitch, V.E.Marquez, and P.M.Blumberg (2006).
Effects on ligand interaction and membrane translocation of the positively charged arginine residues situated along the C1 domain binding cleft in the atypical protein kinase C isoforms.
  J Biol Chem, 281, 33773-33788.  
15822190 M.A.White, and R.G.Anderson (2005).
Signaling networks in living cells.
  Annu Rev Pharmacol Toxicol, 45, 587-603.  
16079140 R.V.Stahelin, J.Wang, N.R.Blatner, J.D.Rafter, D.Murray, and W.Cho (2005).
The origin of C1A-C2 interdomain interactions in protein kinase Calpha.
  J Biol Chem, 280, 36452-36463.  
  15520853 R.Kolesnick, and H.R.Xing (2004).
Inflammatory bowel disease reveals the kinase activity of KSR1.
  J Clin Invest, 114, 1233-1237.  
14570565 D.K.Morrison, and R.J.Davis (2003).
Regulation of MAP kinase signaling modules by scaffold proteins in mammals.
  Annu Rev Cell Dev Biol, 19, 91.  
12855704 F.X.Contreras, A.V.Villar, A.Alonso, R.N.Kolesnick, and F.M.Goñi (2003).
Sphingomyelinase activity causes transbilayer lipid translocation in model and cell membranes.
  J Biol Chem, 278, 37169-37174.  
12941695 J.Müller, D.A.Ritt, T.D.Copeland, and D.K.Morrison (2003).
Functional analysis of C-TAK1 substrate binding and identification of PKP2 as a new C-TAK1 substrate.
  EMBO J, 22, 4431-4442.  
12975377 P.L.Channavajhala, L.Wu, J.W.Cuozzo, J.P.Hall, W.Liu, L.L.Lin, and Y.Zhang (2003).
Identification of a novel human kinase supporter of Ras (hKSR-2) that functions as a negative regulator of Cot (Tpl2) signaling.
  J Biol Chem, 278, 47089-47097.  
12588996 R.A.Janssen, P.N.Kim, J.W.Mier, and D.K.Morrison (2003).
Overexpression of kinase suppressor of Ras upregulates the high-molecular-weight tropomyosin isoforms in ras-transformed NIH 3T3 fibroblasts.
  Mol Cell Biol, 23, 1786-1797.  
12932339 T.Raabe, and U.R.Rapp (2003).
Ras signaling: PP2A puts Ksr and Raf in the right place.
  Curr Biol, 13, R635-R637.  
  12093880 R.Kolesnick (2002).
The therapeutic potential of modulating the ceramide/sphingomyelin pathway.
  J Clin Invest, 110, 3-8.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time.