scholarly journals Retention and stimulus-dependent recycling of dense core vesicle content in neuroendocrine cells

2004 ◽  
Vol 117 (11) ◽  
pp. 2193-2202 ◽  
Author(s):  
R. A. Bauer
Keyword(s):  
Neuroendocrine Cells ◽  
Dense Core ◽  
Dense Core Vesicle ◽  
Vesicle Content

scholarly journals BAIAP3, a C2 domain–containing Munc13 protein, controls the fate of dense-core vesicles in neuroendocrine cells

2017 ◽  
Vol 216 (7) ◽  
pp. 2151-2166 ◽  
Author(s):  
Xingmin Zhang ◽  
Shan Jiang ◽  
Kelly A. Mitok ◽  
Lingjun Li ◽  
Alan D. Attie ◽  
...  
Keyword(s):  
Neuroendocrine Cells ◽  
Dense Core ◽  
Dense Core Vesicle ◽  
Protein Homeostasis ◽  
C2 Domain ◽  
Β Cells ◽  
Calcium Dependent ◽  
Trafficking Pathway ◽  
Protein Receptor ◽  
Golgi Network

Dense-core vesicle (DCV) exocytosis is a SNARE (soluble N-ethylmaleimide–sensitive fusion attachment protein receptor)-dependent anterograde trafficking pathway that requires multiple proteins for regulation. Several C2 domain–containing proteins are known to regulate Ca2+-dependent DCV exocytosis in neuroendocrine cells. In this study, we identified others by screening all (∼139) human C2 domain–containing proteins by RNA interference in neuroendocrine cells. 40 genes were identified, including several encoding proteins with known roles (CAPS [calcium-dependent activator protein for secretion 1], Munc13-2, RIM1, and SYT10) and many with unknown roles. One of the latter, BAIAP3, is a secretory cell–specific Munc13-4 paralog of unknown function. BAIAP3 knockdown caused accumulation of fusion-incompetent DCVs in BON neuroendocrine cells and lysosomal degradation (crinophagy) of insulin-containing DCVs in INS-1 β cells. BAIAP3 localized to endosomes was required for Golgi trans-Golgi network 46 (TGN46) recycling, exhibited Ca2+-stimulated interactions with TGN SNAREs, and underwent Ca2+-stimulated TGN recruitment. Thus, unlike other Munc13 proteins, BAIAP3 functions indirectly in DCV exocytosis by affecting DCV maturation through its role in DCV protein recycling. Ca2+ rises that stimulate DCV exocytosis may stimulate BAIAP3-dependent retrograde trafficking to maintain DCV protein homeostasis and DCV function.

scholarly journals Disruption of the Transmembrane Dense Core Vesicle Proteins IA-2 and IA-2β Causes Female Infertility

Endocrinology ◽  
2006 ◽  
Vol 147 (2) ◽  
pp. 811-815 ◽  
Author(s):  
Atsutaka Kubosaki ◽  
Shinichiro Nakamura ◽  
Anne Clark ◽  
John F. Morris ◽  
Abner L. Notkins
Keyword(s):  
Present Report ◽  
Female Infertility ◽  
Neuroendocrine Cells ◽  
Dense Core ◽  
Structural Proteins ◽  
Corpora Lutea ◽  
Dense Core Vesicle ◽  
Wild Type ◽  
Double Knockout ◽  
Female Mice

Female infertility is a worldwide problem affecting 10–15% of the population. The cause of the infertility in many cases is not known. In the present report, we demonstrate that alterations in two transmembrane structural proteins, IA-2 and IA-2β, located in dense core secretory vesicles (DCV) of many endocrine and neuroendocrine cells, can result in female infertility. IA-2 and IA-2β are best known as major autoantigens in type 1 diabetes, but their normal function has remained an enigma. Recently we showed in mice that deletion of IA-2 and/or IA-2β results in impaired insulin secretion and glucose intolerance. We now report that double knockout (DKO), but not single knockout, female mice are essentially infertile. Vaginal smears showed a totally abnormal estrous cycle, and examination of the ovaries revealed normal-appearing oocytes but the absence of corpora lutea. The LH surge that is required for ovulation occurred in wild-type mice but not in DKO mice. Additional studies showed that the LH level in the pituitary of DKO female mice was decreased compared with wild-type mice. Treatment of DKO females with gonadotropins restored corpora lutea formation. In contrast to DKO female mice, DKO male mice were fertile and LH levels in the serum and pituitary were within the normal range. From these studies we conclude that the DCV proteins, IA-2 and IA-2β, play an important role in LH secretion and that alterations in structural proteins of DCV can result in female infertility.

scholarly journals The Slp4-a Linker Domain Controls Exocytosis through Interaction with Munc18-1·Syntaxin-1a Complex

2006 ◽  
Vol 17 (5) ◽  
pp. 2101-2112 ◽  
Author(s):  
Takashi Tsuboi ◽  
Mitsunori Fukuda
Keyword(s):  
Plasma Membrane ◽  
Specific Interaction ◽  
Inhibitory Effect ◽  
Neuroendocrine Cells ◽  
Dense Core ◽  
Dense Core Vesicle ◽  
Dense Core Vesicles ◽  
Syntaxin 1A ◽  
Vesicle Exocytosis ◽  
Linker Domain

Synaptotagmin-like protein 4-a (Slp4-a)/granuphilin-a is specifically localized on dense-core vesicles in certain neuroendocrine cells and negatively controls dense-core vesicle exocytosis through specific interaction with Rab27A. However, the precise molecular mechanism of its inhibitory effect on exocytosis has never been elucidated and is still a matter of controversy. Here we show by deletion and chimeric analyses that the linker domain of Slp4-a interacts with the Munc18-1·syntaxin-1a complex by directly binding to Munc18-1 and that this interaction promotes docking of dense-core vesicles to the plasma membrane in PC12 cells. Despite increasing the number of plasma membrane docked vesicles, expression of Slp4-a strongly inhibited high-KCl–induced dense-core vesicle exocytosis. The inhibitory effect by Slp4-a is absolutely dependent on the linker domain of Slp4-a, because substitution of the linker domain of Slp4-a by that of Slp5 (the closest isoform of Slp4-a that cannot bind the Munc18-1·syntaxin-1a complex) completely abrogated the inhibitory effect. Our findings reveal a novel docking machinery for dense-core vesicle exocytosis: Slp4-a simultaneously interacts with Rab27A and Munc18-1 on the dense-core vesicle and with syntaxin-1a in the plasma membrane.

scholarly journals The priming factor CAPS1 regulates dense-core vesicle acidification by interacting with rabconnectin3β/WDR7 in neuroendocrine cells

2019 ◽  
Vol 294 (24) ◽  
pp. 9402-9415
Author(s):  
Ellen Crummy ◽  
Muralidharan Mani ◽  
John C. Thellman ◽  
Thomas F. J. Martin
Keyword(s):  
Neuroendocrine Cells ◽  
Dense Core ◽  
Dense Core Vesicle

scholarly journals The EARP Complex and its Interactor EIPR-1 are Required for Cargo Sorting to Dense-Core Vesicles

2016 ◽  
Author(s):  
Irini Topalidou ◽  
Jérôme Cattin-Ortolá ◽  
Andrea L. Pappas ◽  
Kirsten Cooper ◽  
Gennifer E. Merrihew ◽  
...  
Keyword(s):  
Peptide Hormones ◽  
Genetic Screen ◽  
Small Gtpase ◽  
Neuroendocrine Cells ◽  
Dense Core ◽  
Dense Core Vesicle ◽  
Dense Core Vesicles ◽  
Wide Range ◽  
Insulinoma Cells ◽  
Cargo Sorting

AbstractThe dense-core vesicle is a secretory organelle that mediates the regulated release of peptide hormones, growth factors, and biogenic amines. Dense-core vesicles originate from the trans-Golgi of neurons and neuroendocrine cells, but it is unclear how this specialized organelle is formed and acquires its specific cargos. To identify proteins that act in dense-core vesicle biogenesis, we performed a forward genetic screen in Caenorhabditis elegans for mutants defective in dense-core vesicle function. We previously reported the identification of two conserved proteins that interact with the small GTPase RAB-2 to control normal dense-core vesicle cargo-sorting. Here we identify several additional conserved factors important for dense-core vesicle cargo sorting: the WD40 domain protein EIPR-1 and the endosome-associated recycling protein (EARP) complex. By assaying behavior and the trafficking of dense-core vesicle cargos, we show that mutants that lack EIPR-1 or EARP have defects in dense-core vesicle cargo-sorting similar to those of mutants in the RAB-2 pathway. Genetic epistasis data indicate that RAB-2, EIPR-1 and EARP function in a common pathway. In addition, using a proteomic approach in rat insulinoma cells, we show that EIPR-1 physically interacts with the EARP complex. Our data suggest that EIPR-1 is a new component of the EARP complex and that dense-core vesicle cargo sorting depends on the EARP-dependent retrieval of cargo from an endosomal sorting compartment.Author SummaryAnimal cells package and store many important signaling molecules in specialized compartments called dense-core vesicles. Molecules stored in dense-core vesicles include peptide hormones like insulin and small molecule neurotransmitters like dopamine. Defects in the release of these compounds can lead to a wide range of metabolic and mental disorders in humans, including diabetes, depression, and drug addiction. However, it is not well understood how dense-core vesicles are formed in cells and package the appropriate molecules. Here we use a genetic screen in the microscopic worm C. elegans to identify proteins that are important for early steps in the generation of dense-core vesicles, such as packaging the correct molecular cargos in the vesicles. We identify several factors that are conserved between worms and humans and point to a new role for a protein complex that had previously been shown to be important for controlling trafficking in other cellular compartments. The identification of this complex suggests new cellular trafficking events that may be important for the generation of dense-core vesicles.

scholarly journals Role of clathrin in dense core vesicle biogenesis

2017 ◽  
Vol 28 (20) ◽  
pp. 2676-2685 ◽  
Author(s):  
Bhavani S. Sahu ◽  
Paul T. Manna ◽  
James R. Edgar ◽  
Robin Antrobus ◽  
Sushil K. Mahata ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Subcellular Fractionation ◽  
Neuroendocrine Cells ◽  
Dense Core ◽  
Bioactive Molecules ◽  
Dense Core Vesicle ◽  
Data Sets ◽  
Protein Loss ◽  
Associated Proteins

The dense core vesicles (DCVs) of neuroendocrine cells are a rich source of bioactive molecules such as peptides, hormones, and neurotransmitters, but relatively little is known about how they are formed. Using fractionation profiling, a method that combines subcellular fractionation with mass spectrometry, we identified ∼1200 proteins in PC12 cell vesicle-enriched fractions, with DCV-associated proteins showing distinct profiles from proteins associated with other types of vesicles. To investigate the role of clathrin in DCV biogenesis, we stably transduced PC12 cells with an inducible short hairpin RNA targeting clathrin heavy chain, resulting in ∼85% protein loss. DCVs could still be observed in the cells by electron microscopy, but mature profiles were approximately fourfold less abundant than in mock-treated cells. By quantitative mass spectrometry, DCV-associated proteins were found to be reduced approximately twofold in clathrin-depleted cells as a whole and approximately fivefold in vesicle-enriched fractions. Our combined data sets enabled us to identify new candidate DCV components. Secretion assays revealed that clathrin depletion causes a near-complete block in secretagogue-induced exocytosis. Taken together, our data indicate that clathrin has a function in DCV biogenesis beyond its established role in removing unwanted proteins from the immature vesicle.

scholarly journals Quantitative analysis of dense-core vesicle fusion in rodent CNS neurons

2021 ◽  
Vol 2 (1) ◽  
pp. 100325
Author(s):  
Alessandro Moro ◽  
Rein I. Hoogstraaten ◽  
Claudia M. Persoon ◽  
Matthijs Verhage ◽  
Ruud F. Toonen
Keyword(s):  
Quantitative Analysis ◽  
Vesicle Fusion ◽  
Dense Core ◽  
Dense Core Vesicle ◽  
Cns Neurons

scholarly journals HID-1 controls formation of large dense core vesicles by influencing cargo sorting and trans-Golgi network acidification

2017 ◽  
Vol 28 (26) ◽  
pp. 3870-3880 ◽  
Author(s):  
Blake H. Hummer ◽  
Noah F. de Leeuw ◽  
Christian Burns ◽  
Lan Chen ◽  
Matthew S. Joens ◽  
...  
Keyword(s):  
Biochemical Properties ◽  
Neuroendocrine Cells ◽  
Dense Core ◽  
Core Formation ◽  
Dense Core Vesicles ◽  
Atpase Subunit ◽  
Trans Golgi Network ◽  
Large Dense Core Vesicles ◽  
Golgi Network ◽  
Cargo Sorting

Large dense core vesicles (LDCVs) mediate the regulated release of neuropeptides and peptide hormones. They form at the trans-Golgi network (TGN), where their soluble content aggregates to form a dense core, but the mechanisms controlling biogenesis are still not completely understood. Recent studies have implicated the peripheral membrane protein HID-1 in neuropeptide sorting and insulin secretion. Using CRISPR/Cas9, we generated HID-1 KO rat neuroendocrine cells, and we show that the absence of HID-1 results in specific defects in peptide hormone and monoamine storage and regulated secretion. Loss of HID-1 causes a reduction in the number of LDCVs and affects their morphology and biochemical properties, due to impaired cargo sorting and dense core formation. HID-1 KO cells also exhibit defects in TGN acidification together with mislocalization of the Golgi-enriched vacuolar H+-ATPase subunit isoform a2. We propose that HID-1 influences early steps in LDCV formation by controlling dense core formation at the TGN.

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