( ( ( ( The ( clathrin ( coated pit ) ) ) and ) vesicle ) ( ( ( ( ( are ( paradigms ( of ( these structures ) ) ) ) , ) and ) ( are ( ( involved ( in ( receptor-mediated endocytosis ) ) ) ( at ( ( the ( plasma ( ( membrane and ) protein ) ) ) ( sorting ( in ( ( the ( trans-Golgi region ) ) ( of ( virtually ( all ( eukaryotic cells ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ clathrin) (JJ coated) (NN pit)) (CC and) (NP (NN vesicle))) (VP (VP (VBP are) (NP (NP (NNS paradigms)) (PP (IN of) (NP (DT these) (NNS structures))))) (, ,) (CC and) (VP (VBP are) (VP (VBN involved) (PP (IN in) (NP (JJ receptor-mediated) (NNS endocytosis))) (PP (IN at) (NP (NP (DT the) (NN plasma) (NN membrane) (CC and) (NN protein)) (VP (VBG sorting) (PP (IN in) (NP (NP (DT the) (JJ trans-Golgi) (NN region)) (PP (IN of) (NP (RB virtually) (DT all) (JJ eukaryotic) (NNS cells))))))))))) (. .)))
The clathrin coated pit and vesicle are paradigms of these structures, and are involved in receptor-mediated endocytosis at the plasma membrane and protein sorting in the trans-Golgi region of virtually all eukaryotic cells.
(ROOT (S (NP (NNS Vesicles)) (VP (VBP are) (VP (VBN used) (PP (IN during) (NP (NNS endocytosis))) (S (VP (TO to) (VP (VB allow) (S (NP (NNS molecules)) (VP (TO to) (VP (VB enter) (NP (DT the) (NN cell)))))))))) (. .)))