Increasing the length of progerin's isoprenyl anchor does not worsen bone disease or survival in mice with Hutchinson-Gilford progeria syndrome

A Not-So-Ancient Grease History: Click Chemistry and Protein Lipid Modifications

Protein lipid modification involves the attachment of hydrophobic groups to proteins via ester, thioester, amide, or thioether linkages. In this review, the specific click chemical reactions that have been employed to study protein lipid modification and their use for specific labeling applications are first described. This is followed by an introduction to the different types of protein lipid modifications that occur in biology. Next, the roles of click chemistry in elucidating specific biological features including the identification of lipid-modified proteins, studies of their regulation, and their role in diseases are presented. A description of the use of protein-lipid modifying enzymes for specific labeling applications including protein immobilization, fluorescent labeling, nanostructure assembly, and the construction of protein-drug conjugates is presented next. Concluding remarks and future directions are presented in the final section.

A novel approach to tag and identify geranylgeranylated proteins

A recently developed proteomic strategy, the "GG-azide"-labeling approach, is described for the detection and proteomic analysis of geranylgeranylated proteins. This approach involves metabolic incorporation of a synthetic azido-geranylgeranyl analog and chemoselective derivatization of azido-geranylgeranyl-modified proteins by the "click" chemistry, using a tetramethylrhodamine-alkyne. The resulting conjugated proteins can be separated by 1-D or 2-D and pH fractionation, and detected by fluorescence imaging. This method is compatible with downstream LC-MS/MS analysis. Proteomic analysis of conjugated proteins by this approach identified several known geranylgeranylated proteins as well as Rap2c, a novel member of the Ras family. Furthermore, prenylation of progerin in mouse embryonic fibroblast cells was examined using this approach, demonstrating that this strategy can be used to study prenylation of specific proteins. The "GG-azide"-labeling approach provides a new tool for the detection and proteomic analysis of geranylgeranylated proteins, and it can readily be extended to other post-translational modifications.

The posttranslational processing of prelamin A and disease

Human geneticists have shown that some progeroid syndromes are caused by mutations that interfere with the conversion of farnesyl-prelamin A to mature lamin A. For example, Hutchinson-Gilford progeria syndrome is caused by LMNA mutations that lead to the accumulation of a farnesylated version of prelamin A. In this review, we discuss the posttranslational modifications of prelamin A and their relevance to the pathogenesis and treatment of progeroid syndromes.