ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.

ProSAAS is the precursor for some of the most abundant peptides found in mouse brain and other tissues, including peptides named SAAS, PEN, and LEN. Both SAAS and LEN are found in big and little forms due to differential processing. Initial processing of proSAAS is mediated by furin (and/or furin-li...

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Main Authors: Jonathan H Wardman, Lloyd D Fricker
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4141687?pdf=render
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author Jonathan H Wardman
Lloyd D Fricker
author_facet Jonathan H Wardman
Lloyd D Fricker
author_sort Jonathan H Wardman
collection DOAJ
description ProSAAS is the precursor for some of the most abundant peptides found in mouse brain and other tissues, including peptides named SAAS, PEN, and LEN. Both SAAS and LEN are found in big and little forms due to differential processing. Initial processing of proSAAS is mediated by furin (and/or furin-like enzymes) and carboxypeptidase D, while the smaller forms are generated by secretory granule prohormone convertases and carboxypeptidase E. In mouse hypothalamus, PEN and big LEN colocalize with neuropeptide Y. In the present study, little LEN and SAAS were detected in mouse hypothalamus but not in cell bodies of neuropeptide Y-expressing neurons. PEN and big LEN show substantial colocalization in hypothalamus, but big LEN and little LEN do not. An antiserum to SAAS that detects both big and little forms of this peptide did not show substantial colocalization with PEN or big LEN. To further study this, the AtT-20 cells mouse pituitary corticotrophic cell line was transfected with rat proSAAS and the distribution of peptides examined. As found in mouse hypothalamus, only some of the proSAAS-derived peptides colocalized with each other in AtT-20 cells. The two sites within proSAAS that are known to be efficiently cleaved by furin were altered by site-directed mutagenesis to convert the P4 Arg into Lys; this change converts the sequences from furin consensus sites into prohormone convertase consensus sites. Upon expression of the mutated form of proSAAS in AtT-20 cells, there was significantly more colocalization of proSAAS-derived peptides PEN and SAAS. Taken together, these results indicate that proSAAS is initially cleaved in the Golgi or trans-Golgi network by furin and/or furin-like enzymes and the resulting fragments are sorted into distinct vesicles and further processed by additional enzymes into the mature peptides.
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spelling doaj.art-03c40f7f5e6d4b95a79e427babda5e852022-12-22T01:16:09ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0198e10423210.1371/journal.pone.0104232ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.Jonathan H WardmanLloyd D FrickerProSAAS is the precursor for some of the most abundant peptides found in mouse brain and other tissues, including peptides named SAAS, PEN, and LEN. Both SAAS and LEN are found in big and little forms due to differential processing. Initial processing of proSAAS is mediated by furin (and/or furin-like enzymes) and carboxypeptidase D, while the smaller forms are generated by secretory granule prohormone convertases and carboxypeptidase E. In mouse hypothalamus, PEN and big LEN colocalize with neuropeptide Y. In the present study, little LEN and SAAS were detected in mouse hypothalamus but not in cell bodies of neuropeptide Y-expressing neurons. PEN and big LEN show substantial colocalization in hypothalamus, but big LEN and little LEN do not. An antiserum to SAAS that detects both big and little forms of this peptide did not show substantial colocalization with PEN or big LEN. To further study this, the AtT-20 cells mouse pituitary corticotrophic cell line was transfected with rat proSAAS and the distribution of peptides examined. As found in mouse hypothalamus, only some of the proSAAS-derived peptides colocalized with each other in AtT-20 cells. The two sites within proSAAS that are known to be efficiently cleaved by furin were altered by site-directed mutagenesis to convert the P4 Arg into Lys; this change converts the sequences from furin consensus sites into prohormone convertase consensus sites. Upon expression of the mutated form of proSAAS in AtT-20 cells, there was significantly more colocalization of proSAAS-derived peptides PEN and SAAS. Taken together, these results indicate that proSAAS is initially cleaved in the Golgi or trans-Golgi network by furin and/or furin-like enzymes and the resulting fragments are sorted into distinct vesicles and further processed by additional enzymes into the mature peptides.http://europepmc.org/articles/PMC4141687?pdf=render
spellingShingle Jonathan H Wardman
Lloyd D Fricker
ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.
PLoS ONE
title ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.
title_full ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.
title_fullStr ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.
title_full_unstemmed ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.
title_short ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.
title_sort prosaas derived peptides are differentially processed and sorted in mouse brain and att 20 cells
url http://europepmc.org/articles/PMC4141687?pdf=render
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AT lloyddfricker prosaasderivedpeptidesaredifferentiallyprocessedandsortedinmousebrainandatt20cells