Prolyl endopeptidase (PREP) is a post-proline cleaving enzyme. It is involved in the regulation of multiple inositol polyphosphate phosphatase activity implicated in the pathway of inositol 1,4,5 trisphosphate, resulting in the modulation of cytosolic Ca2+ levels. Besides its peptidase activity, PREP was identified as binding partner of tubulin, suggesting that it may participate in microtubule-associate processes. In this paper, we evaluated the expression of PREP mRNA and protein by PCR and Western blot analyses and its colocalization with tubulin by immunofluorescence in adult mouse seminal vesicles. We show that both proteins are cytoplasmic: tubulin is localized at the apical half part of the cell; while PREP has a more diffuse localization, showing a prominent distribution at the apical cytoplasm. These findings support our hypothesis of a specific role of PREP in cytoskeletal rearrangement that occurs during the exocytosis of secretory vesicles, and in particular its association with tubulin filaments. Moreover, it may regulate the Ca2+ levels, which promotes the final step of the vesicular exocytosis, namely the fusion of the vesicles with the plasma membrane. These results strongly suggest for a pivotal role of PREP in vesicle exocytosis as well as in the physiology of mouse seminal vesicles.
Summary Prolyl endopeptidase (PREP) is a post-proline cleaving enzyme. It is involved in the regulation of multiple inositol polyphosphate phosphatase activity implicated in the pathway of inositol 1,4,5-trisphosphate, resulting in the modulation of cytosolic Ca2+ levels. Besides its peptidase activity, PREP was identified as a binding partner of tubulin, suggesting that it may participate in microtubule-associate processes. In this paper, we evaluated the expression of PREP mRNA and protein by polymerase chain reaction and western blot analyses and its co-localization with tubulin by immunofluorescence in adult mouse seminal vesicles. We showed that both proteins are cytoplasmic: tubulin is localized at the apical half part of the cell, while PREP has a more diffuse localization, showing a prominent distribution at the apical cytoplasm. These findings support our hypothesis of a specific role for PREP in cytoskeletal rearrangement that occurs during the exocytosis of secretory vesicles, and in particular its association with tubulin filaments. Moreover, it may regulate Ca2+ levels, and promote the final step of vesicular exocytosis, namely the fusion of the vesicles with the plasma membrane. These results strongly suggest that there is a pivotal role for PREP in vesicle exocytosis, as well as in the physiology of mouse seminal vesicles.
Study on PREP localization in mouse seminal vesicles and its possible involvement during regulated exocytosis
Venditti MassimoWriting – Original Draft Preparation
;Santillo AlessandraData Curation
;Minucci Sergio
Writing – Review & Editing
2019
Abstract
Summary Prolyl endopeptidase (PREP) is a post-proline cleaving enzyme. It is involved in the regulation of multiple inositol polyphosphate phosphatase activity implicated in the pathway of inositol 1,4,5-trisphosphate, resulting in the modulation of cytosolic Ca2+ levels. Besides its peptidase activity, PREP was identified as a binding partner of tubulin, suggesting that it may participate in microtubule-associate processes. In this paper, we evaluated the expression of PREP mRNA and protein by polymerase chain reaction and western blot analyses and its co-localization with tubulin by immunofluorescence in adult mouse seminal vesicles. We showed that both proteins are cytoplasmic: tubulin is localized at the apical half part of the cell, while PREP has a more diffuse localization, showing a prominent distribution at the apical cytoplasm. These findings support our hypothesis of a specific role for PREP in cytoskeletal rearrangement that occurs during the exocytosis of secretory vesicles, and in particular its association with tubulin filaments. Moreover, it may regulate Ca2+ levels, and promote the final step of vesicular exocytosis, namely the fusion of the vesicles with the plasma membrane. These results strongly suggest that there is a pivotal role for PREP in vesicle exocytosis, as well as in the physiology of mouse seminal vesicles.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
