Zielmembran

Zielmembran, also known as target membrane, refers to the specific cellular membrane that a protein or other molecule is destined to associate with or traverse. This targeting is a crucial aspect of cellular organization and function, ensuring that molecules reach their correct locations within or outside the cell. Proteins destined for secretion, insertion into other organelles, or integration into the plasma membrane are synthesized in ribosomes, often on the endoplasmic reticulum. During or shortly after synthesis, specific signal sequences within the protein are recognized by cellular machinery, such as signal recognition particles, which then direct the ribosome-mRNA complex to the appropriate target membrane. For proteins destined for organelles like mitochondria or chloroplasts, different targeting mechanisms are employed, often involving protein translocators embedded in the outer and inner membranes of these organelles. The precise recognition and docking of molecules to their target membranes are mediated by a complex interplay of protein-protein interactions and lipid compositions, ensuring accurate delivery and preventing mistargeting, which can lead to cellular dysfunction.