title: Inhibitors of protein geranylgeranyltransferase I and Rab geranylgeranyltransferase identified from a library of allenoate-derived compounds.
abstract: Protein geranylgeranylation is critical for the function of a number of proteins such as RhoA, Rac, and Rab. Protein geranylgeranyltransferase I (GGTase-I) and Rab geranylgeranyltransferase (RabGGTase) catalyze these modifications. In this work, we first describe the identification and characterization of small molecule inhibitors of GGTase-I (GGTI) with two novel scaffolds from a library consisting of allenoate-derived compounds. These compounds exhibit specific inhibition of GGTase-I and act by competing with a substrate protein. Derivatization of a carboxylic acid emanating from the core ring of one of the GGTI compounds dramatically improves their cellular activity. The improved GGTI compounds inhibit proliferation of a variety of human cancer cell lines and cause G(1) cell cycle arrest and induction of p21(CIP1/WAF1). We also report the identification of novel small molecule inhibitors of RabGGTase. These compounds were identified first by screening our GGTI compounds for those that also exhibited RabGGTase inhibition. This led to the discovery of a common structural feature for RabGGTase inhibitors: the presence of a characteristic six-atom aliphatic tail attached to the penta-substituted pyrrolidine core. Further screening led to the identification of compounds with preferential inhibition of RabGGTase. These compounds inhibit RabGGTase activity by competing with the substrate protein. These novel compounds may provide valuable reagents to study protein geranylgeranylation.
authors.affiliation: Microbiology, Immunology, and Molecular Genetics, Jonsson Comprehensive Cancer Center, University of California-Los Angeles, 609 Charles E. Young Drive, Los Angeles, CA 90095, USA.
authors.forename: Masaru
authors.initials: M
authors.lastname: Watanabe
authors.forename: Hannah D G
authors.initials: HD
authors.lastname: Fiji
authors.forename: Lea
authors.initials: L
authors.lastname: Guo
authors.forename: Lai
authors.initials: L
authors.lastname: Chan
authors.forename: Sape S
authors.initials: SS
authors.lastname: Kinderman
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Slamon
authors.forename: Ohyun
authors.initials: O
authors.lastname: Kwon
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Tamanoi
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000818:Animals; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D016193:G1 Phase / Q000187:drug effects*; D006801:Humans; D020014:K562 Cells; D051379:Mice; D015394:Molecular Structure; D041681:NIH 3T3 Cells; D009281:Naphthalenes / Q000737:chemistry / Q000494:pharmacology*; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D020691:rab GTP-Binding Proteins / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: C493956:CDKN1A protein, human; C493957:Cdkn1a protein, mouse; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004791:Enzyme Inhibitors; D009281:Naphthalenes; C066737:RHOA protein, human; D019883:Alkyl and Aryl Transferases; C075607:Rab geranylgeranyltransferase; C083291:geranylgeranyltransferase type-I; C526380:RhoA protein, mouse; D020691:rab GTP-Binding Proteins; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein; C110055:allenolic acid