Signal peptide

From WikiMD's Wellness Encyclopedia

Signal Peptide

A Signal peptide (or signal sequence, leader sequence, leader peptide) is a short (3-60 amino acids long) peptide chain that directs the post-translational transport of a protein.

Function[edit | edit source]

Signal peptides are used to direct the protein to certain locations within the cell. They are usually found at the N-terminus of the protein sequence and are cleaved off by a signal peptidase after the protein is transported.

Structure[edit | edit source]

The structure of a signal peptide varies between different proteins, but they generally contain three regions: a positively charged n-region, a hydrophobic h-region, and a polar c-region.

Signal Recognition Particle[edit | edit source]

The Signal Recognition Particle (SRP) is a protein-RNA complex that recognizes and targets specific proteins to the endoplasmic reticulum in eukaryotes and the plasma membrane in prokaryotes.

Secretory Proteins[edit | edit source]

Secretory proteins are synthesized on ribosomes bound to the ER. They have signal peptides that direct them into the ER lumen, where they are folded and modified.

See Also[edit | edit source]

References[edit | edit source]

Contributors: Prab R. Tumpati, MD