dibasic protein processing

Definition

Target type: biologicalprocess

Any protein processing achieved by the cleavage of a peptide bond after two basic amino acids within a protein. [GOC:al]

Dibasic protein processing is a crucial step in the maturation of many proteins, particularly those destined for secretion or localization to specific cellular compartments. The process involves the removal of dibasic amino acid residues (typically lysine-lysine or arginine-lysine) from the N-terminus of a precursor protein, often followed by further processing events like acetylation. This removal is catalyzed by a family of enzymes called dibasic processing enzymes (DPEs), which are highly specific for their target substrates and exhibit distinct cellular localization.

The dibasic processing pathway is initiated when a precursor protein is synthesized with a dibasic motif at its N-terminus. This motif acts as a signal sequence that directs the protein to the endoplasmic reticulum (ER), where it undergoes further processing. Within the ER lumen, DPEs recognize and cleave the dibasic motif, releasing the mature protein. The cleaved dibasic motif is then degraded, preventing its reattachment to the protein.

The precise mechanism by which DPEs recognize and cleave dibasic motifs remains to be fully elucidated. However, it is believed that DPEs bind to the dibasic motif through electrostatic interactions between their active site and the positively charged residues of the motif. This binding triggers a conformational change in the enzyme, bringing the catalytic residues into proximity with the peptide bond that needs to be cleaved.

The dibasic processing pathway is essential for the proper function of a wide range of proteins, including hormones, enzymes, and signaling molecules. It plays a crucial role in regulating protein trafficking, stability, and activity. For instance, the removal of a dibasic motif from a secreted protein can prevent its aggregation and ensure its efficient secretion from the cell.

In summary, dibasic protein processing is a highly regulated process that involves the precise removal of dibasic motifs from precursor proteins. This process is essential for protein maturation, localization, and function, highlighting its significance in maintaining cellular homeostasis and organismal development.'
"

Proteins (1)

Compounds (4)