1 40 1 Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. URL Address <a href="http://doi.org/10.1016/s0006-8993(01)02304-6" target="_blank" rel="noreferrer noopener">http://doi.org/10.1016/s0006-8993(01)02304-6</a> Pages 13–25 Issue 1 Volume 903 Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Par-4 is a synaptic protein that regulates neurite outgrowth by altering calcium homeostasis and transcription factor AP-1 activation. Publisher An entity responsible for making the resource available Brain research Date A point or period of time associated with an event in the lifecycle of the resource 2001 2001-06 Subject The topic of the resource *Intracellular Signaling Peptides and Proteins; Animals; Antibodies; Apoptosis Regulatory Proteins; Calcium Signaling/*physiology; Calcium/*metabolism; Carrier Proteins/genetics/immunology/*metabolism; Cell Compartmentation/physiology; Cerebral Cortex/cytology; Gene Expression/physiology; Hippocampus/cytology; Homeostasis/physiology; Inbred C57BL; Mice; Nerve Growth Factor/pharmacology; Neurites/*metabolism; Neurons/metabolism/ultrastructure; PC12 Cells; Rats; Synaptosomes/metabolism; Transcription Factor AP-1/*metabolism; Transcriptional Activation/drug effects/physiology; Transfection Creator An entity primarily responsible for making the resource Guo Q; Xie J; Chang X; Zhang X; Du H Description An account of the resource Although Par-4 (prostate apoptosis response-4) is involved in initiation of neurodegenerative cascades associated with certain neurodegenerative disorders, normal physiological roles of Par-4 in neurons have remained elusive. It was recently reported that Par-4 protein levels could be regulated at translational level in synaptic terminals following apoptotic insults, suggesting that Par-4 might play a role in synaptic function. We report that Par-4 is a synaptic protein preferably localized in postsynaptic density (PSD). The expression of Par-4 in synaptosome preparations and PSDs are developmentally and regionally regulated. Synaptic Par-4 is enriched in the cerebral cortex and the hippocampus, but not in the cerebellum. In vitro as well as in vivo experiments demonstrate that the levels of synaptic Par-4 increase as the neurons mature. Overexpression of Par-4 in transfected PC12 cells inhibits nerve growth factor (NGF)-induced cellular differentiation and neurite outgrowth by a mechanism involving aberrant elevation of intracellular calcium levels and suppression of activation of the transcription factor AP-1. The actions of Par-4 were consistently blocked by co-expression of the dominant negative regulator of Par-4 activity (the leucine zipper domain of Par-4). Since the leucine zipper domain of Par-4 (Leu.zip) may mediate protein–protein interactions, the results indicate that the actions of Par-4 require its interaction with other protein(s) or dimerization with itself. These results suggest that Par-4 may play an important role in postsynaptic signal transduction and regulation of cellular pathways associated with cellular differentiation and neurite outgrowth. Identification of Par-4 as a novel synaptic protein may have significant implications in understanding the mechanisms of synaptic functions in physiological and pathological settings. Identifier An unambiguous reference to the resource within a given context <a href="http://doi.org/10.1016/s0006-8993(01)02304-6" target="_blank" rel="noreferrer noopener">10.1016/s0006-8993(01)02304-6</a> Rights Information about rights held in and over the resource Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s). *Intracellular Signaling Peptides and Proteins 2001 Animals Antibodies Apoptosis Regulatory Proteins Brain research Calcium Signaling/*physiology Calcium/*metabolism Carrier Proteins/genetics/immunology/*metabolism Cell Compartmentation/physiology Cerebral Cortex/cytology Chang X Du H Gene Expression/physiology Guo Q Hippocampus/cytology Homeostasis/physiology Inbred C57BL Mice Nerve Growth Factor/pharmacology Neurites/*metabolism Neurons/metabolism/ultrastructure PC12 Cells Rats Synaptosomes/metabolism Transcription Factor AP-1/*metabolism Transcriptional Activation/drug effects/physiology Transfection Xie J Zhang X