Murine immunoglobulin kappa chain leader signal peptide
N-terminal secretory signal peptide from the murine immunoglobulin kappa light chain. Placed at the N-terminus of a protein, it directs the protein into the endoplasmic reticulum for secretion, and signal peptidase then removes it. Used to secrete antibody chains, cytokines, and secreted reporters from mammalian cells.
Origin: Murine immunoglobulin kappa light chain
Characteristics
Like other signal peptides, it has a tripartite structure of a positively charged n-region, a hydrophobic core, and a polar c-region that contains the signal peptidase cleavage site. It is cleaved co-translationally in the ER lumen, so the mature secreted protein does not carry it. Whether the cargo is secreted or retained in the membrane depends on the sequences that follow the signal peptide.
Applications: N-terminal secretion signal for antibody chains, cytokines, growth factors, and secreted reporters expressed from plasmid or viral vectors in mammalian cells. Replaces the native signal peptide when a heterologous cargo must enter the secretory pathway.
Limitations: Cleavage and secretion efficiency depend on the downstream cargo sequence, so the signal peptide does not work equally well for every protein. Species-matched signal peptides can perform better in some host cells. The Igκ-specific efficiency data are not yet recorded in this entry.
Sequence
References
- von Heijne et al. (1990). The signal peptide. J Membr Biol - vonHeijne 1990 Signal Peptides