Editing Transmembrane domain (section)

=== Cytosolic recognition factors ===
Cytosolic recognition factors are thought to use two distinct strategies.<ref name=":0" /> In the co-translational strategy the recognition and shielding are coupled to protein synthesis. [[Genome-wide association study|Genome wide association studies]] indicate the majority of membrane proteins targeting the endoplasmic reticulum are handled by the [[signal recognition particle]] which is bound to the ribosomal exit tunnel and initiates recognition and shielding as protein is translated. The second strategy involves tail-anchored proteins, defined by a single TMD located close to the carboxyl terminus of the membrane protein. Once translation is completed, the tail-anchored TMD remains in the ribosomal exit tunnel, and an ATPase mediates targeting to the endoplasmic reticulum. Examples of shuttling factors include TRC40 in higher eukaryotes and Get3 in yeast. Furthermore, general TMD-binding factors protect against aggregation and other disrupting interactions. [[SGTA]] and [[calmodulin]] are two well-known general TMD-binding factors. Quality control of membrane proteins involve TMD-binding factors that are linked to [[ubiquitin]]ation [[proteasome]] system.