Grb7 SH2 domain structure and interactions with a cyclic peptide inhibitor of cancer cell migration and proliferation

Abstract

Background: Human growth factor receptor bound protein 7 (Grb7) is an adapter protein that mediates the coupling of tyrosine kinases with their downstream signaling pathways. Grb7 is frequently overexpressed in invasive and metastatic human cancers and is implicated in cancer progression via its interaction with the ErbB2 receptor and focal adhesion kinase (FAK) that play critical roles in cell proliferation and migration. It is thus a prime target for the development of novel anti-cancer therapies. Recently, an inhibitory peptide (G7-18NATE) has been developed which binds specifically to the Grb7 SH2 domain and is able to attenuate cancer cell proliferation and migration in various cancer cell lines.

Binding and Function of Phosphotyrosines of the Ephrin A2 (EphA2) Receptor Using Synthetic Sterile α Motif (SAM) Domains

“…This change arises due to the formation of a larger molecular weight complex because Grb7 SH2 is a dimer and the Tyr(P) binding interface and the dimerization interface are different (35, 36) (data not shown). However, it is not clear to what extent, if any, Tyr(P) binding alters the dimerization of Grb7 SH2 (35,36,37). Upon the addition of SHIP2 SAM to the premixed complex of Grb7 SH2 (labeled)-EphA2.pY921, we saw a change in intensity of several but not all of the dispersed resonances compared with the spectrum of Grb7 SH2 bound to Eph.pY921 (Fig.…”

Grb7 - A Newly Emerging Target in Pancreatic Cancer

“…As shown in Fig. 4, the Grb7 SH2 domain comprises two pairs of anti-parallel -sheets flanked by a pair of -helices (Porter et al, 2007). Such a structure is a general feature of SH2 domain proteins (Pawson, 1994;Margolis et al, 1994).…”

“…The binding affinity of the G7-18NATE prototype peptide has been characterized extensively by isothermal titration calorimetry (Porter et al, 2007;Spuches et al, 2007;Ambaye et al, 2011a), surface plasmon resonance (Gunzburg et al, 2010) and ELISA assays (Luzy et al, 2008). Such investigations provide invaluable information that should guide the further optimization of this lead polypeptide.…”

“…This is because the SH2 domain commences the first and hence the fate determining step in the entire process of Grb7 dependent signalling . Moreover, the SH2 domain possesses a well defined and characterized binding pocket amenable to a variety of ligand design efforts (Porter et al, 2007). In addition, the requirement of the SH2 domain to bind to Grb7's myriad of upstream partners is generally conserved Han et al, 2001) where a minimal recognition motif is put forth.…”

“…The experimental structure of Grb7 SH2 domain has been solved both by NMR and X-ray crystallography (Porter et al, 2007;Ivancic et al, 2003). The crystal structure is solved to 2.1 Å resolution with an overall tetrameric assembly by our group (PDB ID: 2QMS).…”