need on iseloomulikud ühekordselt membraane läbivatele valkudele (tüüp II, III ja IV klassid), millel on tsütoplasmavõrgustiku membraani läbiv piirkond, mis neid seal kinni hoiab, Single-pass transmembrane protein (type II, III, and IV) possessing a membrane-spanning domain which targets the protein to the ER membrane. Typical features of signal-anchors are the presence of positively charged residues on the amino terminal side followed by an apolar segment of approx. 20 residues.