Lyn kinase N-terminal myristoylation and palmitoylation sequence
N-terminal sequence of Lyn, a Src family tyrosine kinase, that directs myristoylation and palmitoylation. Fused to a protein of interest it anchors the protein to the inner leaflet of the plasma membrane. It is a short, genetically encoded lipid anchor.
Origin: N terminus of Lyn, a Src family tyrosine kinase
Characteristics
Encodes GCIKSKRKDG (10 amino acids, 30 nucleotides). The Lyn N-terminal sequence directs myristoylation and palmitoylation, which targets a fused GFP to the inner monolayer of the plasma membrane. In RAW264.7 macrophages the GFP fusion (PM-GFP) recovers after photobleaching with a mobile fraction of 1.10 ± 0.04 and t1/2 of 15 ± 2 s (D 1.5 × 10⁻¹⁰ cm²/s), similar to phospholipids. At the phagocytic cup the mobile fraction falls to 0.36 ± 0.01, and this requires Src-family kinase activity.
Applications: Targets GFP to the inner leaflet of the plasma membrane in RAW264.7 macrophages (PM-GFP). Used as a FRAP probe for the lateral mobility of diacylated proteins, a model for lipid-anchored Src-family kinases, including at the phagocytic cup during uptake of IgG-opsonized beads.
Limitations: Localization is not confined to the plasma membrane: PM-GFP shows varying endomembrane staining depending on expression level in RAW264.7 macrophages. The anchor is not neutral at signaling sites: PM-GFP mobile fraction falls to 0.36 ± 0.01 at the phagocytic cup in a Src-family kinase-dependent manner, so it does not report free diffusion there.
Sequence
References
- Corbett-Nelson et al. (2006). Signaling-dependent immobilization of acylated proteins in the inner monolayer of the plasma membrane. J Cell Biol - Corbett-Nelson 2006 Acylated Proteins