scholarly journals Retromer retrieves the Wilson Disease protein, ATP7B from lysosomes in a copper-dependent mode

2020 ◽  
Author(s):  
Santanu Das ◽  
Saptarshi Maji ◽  
Ruturaj ◽  
Indira Bhattacharya ◽  
Tanusree Saha ◽  
...  
Keyword(s):  
Super Resolution ◽  
Copper Level ◽  
Copper Transporter ◽  
Copper Chelation ◽  
Proximity Ligation ◽  
High Copper ◽  
Core Member ◽  
Disease Protein ◽  
Cellular Copper ◽  
Golgi Network

ATP7B utilizes lysosomal exocytosis to export copper from hepatocytes. We investigated the fate of ATP7B, post-copper export. At high copper ATP7B traffics to lysosomes and upon subsequent copper chelation, returns to Trans Golgi Network. At high copper, ATP7B co-localizes with lysosomal marker, Lamp1 and the core member of retromer complex, Vps35. Knocking down VPS35 did not alter copper-responsive vesicularization of ATP7B; rather upon subsequent copper chelation, ATP7B failed to relocalize to TGN that could be rescued by overexpressing wtVPS35. Using super-resolution microscopy and proximity ligation assays we demonstrate that VPS35 and ATP7B are juxtaposed on the same lysosomal compartment and their interaction is indirect. Utilizing in-cell photoamino acid-based UV-crosslinking and subsequent immunoprecipitation, we detected ATP7B and retromer subunits, VPS35 and VPS26 in a large complex in high copper conditions, hence confirming their interaction. We demonstrate that retromer regulates lysosome to TGN trafficking of the copper transporter ATP7B and it is dependent upon cellular copper level.

scholarly journals Retromer retrieves the Wilson disease protein ATP7B from endolysosomes in a copper-dependent manner

2020 ◽  
Vol 133 (24) ◽  
pp. jcs246819 ◽  
Author(s):  
Santanu Das ◽  
Saptarshi Maji ◽  
Ruturaj ◽  
Indira Bhattacharya ◽  
Tanusree Saha ◽  
...  
Keyword(s):  
Wilson Disease ◽  
Dependent Manner ◽  
Copper Transporter ◽  
Copper Chelation ◽  
Trans Golgi Network ◽  
Wilson Disease Protein ◽  
Retromer Complex ◽  
High Copper ◽  
Disease Protein ◽  
Golgi Network

ABSTRACTThe Wilson disease protein, ATP7B maintains copper (herein referring to the Cu+ ion) homeostasis in the liver. ATP7B traffics from trans-Golgi network to endolysosomes to export excess copper. Regulation of ATP7B trafficking to and from endolysosomes is not well understood. We investigated the fate of ATP7B after copper export. At high copper levels, ATP7B traffics primarily to acidic, active hydrolase (cathepsin-B)-positive endolysosomes and, upon subsequent copper chelation, returns to the trans-Golgi network (TGN). At high copper, ATP7B colocalizes with endolysosomal markers and with a core member of retromer complex, VPS35. Knocking down VPS35 did not abrogate the copper export function of ATP7B or its copper-responsive anterograde trafficking to vesicles; rather upon subsequent copper chelation, ATP7B failed to relocalize to the TGN, which was rescued by overexpressing wild-type VPS35. Overexpressing mutants of the retromer complex-associated proteins Rab7A and COMMD1 yielded a similar non-recycling phenotype of ATP7B. At high copper, VPS35 and ATP7B are juxtaposed on the same endolysosome and form a large complex that is stabilized by in vivo photoamino acid labeling and UV-crosslinking. We demonstrate that retromer regulates endolysosome to TGN trafficking of copper transporter ATP7B in a manner that is dependent upon intracellular copper.

scholarly journals COMMD1 and PtdIns(4,5)P2 interaction maintain ATP7B copper transporter trafficking fidelity in HepG2 cells

2019 ◽  
Author(s):  
Davis J. Stewart ◽  
Kristopher K. Short ◽  
Breanna N. Maniaci ◽  
Jason L. Burkhead
Keyword(s):  
Protein Trafficking ◽  
Early Endosome ◽  
Copper Accumulation ◽  
Direct Function ◽  
Copper Transporter ◽  
Membrane Protein Trafficking ◽  
Copper Balance ◽  
Cellular Copper ◽  
Golgi Network ◽  
Specific Membrane

ABSTRACTCopper-responsive intracellular ATP7B trafficking is critical to maintain copper balance in mammalian hepatocytes and thus organismal copper levels. The COMMD1 protein binds both the ATP7B copper transporter and phosphatidylinositol (4,5)-bisphosphate (PtdIns(4,5)P2), while COMMD1 loss causes hepatocyte copper accumulation. Although it is clear that COMMD1 is included in endocytic trafficking complexes, a direct function for COMMD1 in ATP7B trafficking has not been defined. In this study, experiments using quantitative reveal that COMMD1 modulates the copper-responsive ATP7B trafficking through recruitment to PtdIns(4,5)P2. Decreased COMMD1 abundance results in loss of ATP7B from lysosomes and thetrans-Golgi network (TGN) in high copper conditions, while excess expression of COMMD1 also disrupts ATP7B trafficking and TGN structure. Overexpression of COMMD1 mutated to inhibit PtdIns(4,5)P2binding has little impact on ATP7B trafficking. A mechanistic PtdIns(4,5)P2-mediated function for COMMD1 is proposed that is consistent with decreased cellular copper export due to disruption of the ATP7B trafficking itinerary and accumulation in the early endosome when COMMD1 is depleted. PtdIns(4,5)P2interaction with COMMD1 as well as COMMD1 abundance may both be important in maintenance of specific membrane protein trafficking pathways.SUMMARYQuantitative analysis of 3D protein colocalization defines the cellular function of COMMD1 in maintenance of ATP7B copper transporter trafficking fidelity and the importance of PtdIns(4,5)P2in this action.

Roles of COMM-domain-containing 1 in stability and recruitment of the copper-transporting ATPase in a mouse hepatoma cell line

2010 ◽  
Vol 429 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Takamitsu Miyayama ◽  
Daisuke Hiraoka ◽  
Fumika Kawaji ◽  
Emi Nakamura ◽  
Noriyuki Suzuki ◽  
...  
Keyword(s):  
Cell Line ◽  
Hepatoma Cell ◽  
Copper Accumulation ◽  
Copper Level ◽  
Hepatoma Cell Line ◽  
Copper Transporter ◽  
Trans Golgi Network ◽  
Mouse Hepatoma ◽  
Cytoplasmic Vesicles ◽  
Golgi Network

A novel function of COMMD1 {COMM [copper metabolism MURR1 (mouse U2af1-rs1 region 1)]-domain-containing 1}, a protein relevant to canine copper toxicosis, was examined in the mouse hepatoma cell line Hepa 1-6 with multi-disciplinary techniques consisting of molecular and cellular biological techniques, speciation and elemental imaging. To clarify the function of COMMD1, COMMD1-knockdown was accomplished by introducing siRNA (small interfering RNA) into the cells. Although COMMD1-knockdown did not affect copper incorporation, it inhibited copper excretion, resulting in copper accumulation, which predominantly existed in the form bound to MT (metallothionein). It is known that the liver copper transporter Atp7b (ATP-dependent copper transporter 7β), localizes on the trans-Golgi network membrane under basal copper conditions and translocates to cytoplasmic vesicles to excrete copper when its concentration exceeds a certain threshold, with the vesicles dispersing in the periphery of the cell. COMMD1-knockdown reduced the expression of Atp7b, and abolished the relocation of Atp7b back from the periphery to the trans-Golgi network membrane when the copper concentration was reduced by treatment with a Cu(I) chelator. The same phenomena were observed during COMMD1-knockdown when another Atp7b substrate, cis-diamminedichloroplatinum, and its sequestrator, glutathione ethylester, were applied. These results suggest that COMMD1 maintains the amount of Atp7b and facilitates recruitment of Atp7b from cytoplasmic vesicles to the trans-Golgi network membrane, i.e. COMMD1 is required to shuttle Atp7b when the intracellular copper level returns below the threshold.

scholarly journals Cargo sorting zones in the trans-Golgi network visualized by super-resolution confocal live imaging microscopy in plants

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yutaro Shimizu ◽  
Junpei Takagi ◽  
Emi Ito ◽  
Yoko Ito ◽  
Kazuo Ebine ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
High Speed ◽  
Super Resolution ◽  
Adaptor Protein ◽  
Transport Proteins ◽  
3D Localization ◽  
Golgi Network ◽  
Distinct Distribution ◽  
Vacuolar Trafficking ◽  
Cargo Sorting

AbstractThe trans-Golgi network (TGN) has been known as a key platform to sort and transport proteins to their final destinations in post-Golgi membrane trafficking. However, how the TGN sorts proteins with different destinies still remains elusive. Here, we examined 3D localization and 4D dynamics of TGN-localized proteins of Arabidopsis thaliana that are involved in either secretory or vacuolar trafficking from the TGN, by a multicolor high-speed and high-resolution spinning-disk confocal microscopy approach that we developed. We demonstrate that TGN-localized proteins exhibit spatially and temporally distinct distribution. VAMP721 (R-SNARE), AP (adaptor protein complex)−1, and clathrin which are involved in secretory trafficking compose an exclusive subregion, whereas VAMP727 (R-SNARE) and AP-4 involved in vacuolar trafficking compose another subregion on the same TGN. Based on these findings, we propose that the single TGN has at least two subregions, or “zones”, responsible for distinct cargo sorting: the secretory-trafficking zone and the vacuolar-trafficking zone.

scholarly journals Regulation of murine copper homeostasis by members of the COMMD protein family

2020 ◽  
Vol 14 (1) ◽  
pp. dmm045963
Author(s):  
Amika Singla ◽  
Qing Chen ◽  
Kohei Suzuki ◽  
Jie Song ◽  
Alina Fedoseienko ◽  
...  
Keyword(s):  
Copper Homeostasis ◽  
Copper Accumulation ◽  
Copper Transporter ◽  
Copper Excretion ◽  
Copper Absorption ◽  
Hepatic Copper ◽  
High Copper ◽  
Molecular Machinery ◽  
And Function

ABSTRACTCopper is an essential transition metal for all eukaryotes. In mammals, intestinal copper absorption is mediated by the ATP7A copper transporter, whereas copper excretion occurs predominantly through the biliary route and is mediated by the paralog ATP7B. Both transporters have been shown to be recycled actively between the endosomal network and the plasma membrane by a molecular machinery known as the COMMD/CCDC22/CCDC93 or CCC complex. In fact, mutations in COMMD1 can lead to impaired biliary copper excretion and liver pathology in dogs and in mice with liver-specific Commd1 deficiency, recapitulating aspects of this phenotype. Nonetheless, the role of the CCC complex in intestinal copper absorption in vivo has not been studied, and the potential redundancy of various COMMD family members has not been tested. In this study, we examined copper homeostasis in enterocyte-specific and hepatocyte-specific COMMD gene-deficient mice. We found that, in contrast to effects in cell lines in culture, COMMD protein deficiency induced minimal changes in ATP7A in enterocytes and did not lead to altered copper levels under low- or high-copper diets, suggesting that regulation of ATP7A in enterocytes is not of physiological consequence. By contrast, deficiency of any of three COMMD genes (Commd1, Commd6 or Commd9) resulted in hepatic copper accumulation under high-copper diets. We found that each of these deficiencies caused destabilization of the entire CCC complex and suggest that this might explain their shared phenotype. Overall, we conclude that the CCC complex plays an important role in ATP7B endosomal recycling and function.

scholarly journals Essential Roles in Development and Pigmentation for the Drosophila Copper Transporter DmATP7

2006 ◽  
Vol 17 (1) ◽  
pp. 475-484 ◽  
Author(s):  
Melanie Norgate ◽  
Esther Lee ◽  
Adam Southon ◽  
Ashley Farlow ◽  
Philip Batterham ◽  
...  
Keyword(s):  
Copper Homeostasis ◽  
Cellular Level ◽  
Loss Of Function ◽  
Neuronal Function ◽  
Copper Transporter ◽  
Disease Phenotypes ◽  
In Vivo Analysis ◽  
Cellular Copper ◽  
P Type

Defects in the mammalian Menkes and Wilson copper transporting P-type ATPases cause severe copper homeostasis disease phenotypes in humans. Here, we find that DmATP7, the sole Drosophila orthologue of the Menkes and Wilson genes, is vital for uptake of copper in vivo. Analysis of a DmATP7 loss-of-function allele shows that DmATP7 is essential in embryogenesis, early larval development, and adult pigmentation and is probably required for copper uptake from the diet. These phenotypes are analogous to those caused by mutation in the mouse and human Menkes genes, suggesting that like Menkes, DmATP7 plays at least two roles at the cellular level: delivering copper to cuproenzymes required for pigmentation and neuronal function and removing excess cellular copper via facilitated efflux. DmATP7 displays a dynamic and unexpected expression pattern in the developing embryo, implying novel functions for this copper pump and the lethality observed in DmATP7 mutant flies is the earliest seen for any copper homeostasis gene.

scholarly journals Laccases Involved in 1,8-Dihydroxynaphthalene Melanin Biosynthesis in Aspergillus fumigatus Are Regulated by Developmental Factors and Copper Homeostasis

2013 ◽  
Vol 12 (12) ◽  
pp. 1641-1652 ◽  
Author(s):  
Srijana Upadhyay ◽  
Guadalupe Torres ◽  
Xiaorong Lin
Keyword(s):  
Immune Responses ◽  
Aspergillus Fumigatus ◽  
Gene Cluster ◽  
Gene Expression Pattern ◽  
Copper Homeostasis ◽  
Copper Level ◽  
Fungal Virulence ◽  
Copper Transporter ◽  
Melanin Biosynthesis ◽  
Content Type

ABSTRACTAspergillus fumigatusproduces heavily melanized infectious conidia. The conidial melanin is associated with fungal virulence and resistance to various environmental stresses. This 1,8-dihydroxynaphthalene (DHN) melanin is synthesized by enzymes encoded in a gene cluster inA. fumigatus, including two laccases, Abr1 and Abr2. Although this gene cluster is not conserved in all aspergilli, laccases are critical for melanization in all species examined. Here we show that the expression ofA. fumigatuslaccases Abr1/2 is upregulated upon hyphal competency and drastically increased during conidiation. The Abr1 protein is localized at the surface of stalks and conidiophores, but not in young hyphae, consistent with the gene expression pattern and its predicted role. The induction of Abr1/2 upon hyphal competency is controlled by BrlA, the master regulator of conidiophore development, and is responsive to the copper level in the medium. We identified a developmentally regulated putative copper transporter, CtpA, and found that CtpA is critical for conidial melanization under copper-limiting conditions. Accordingly, disruption of CtpA enhanced the induction ofabr1andabr2, a response similar to that induced by copper starvation. Furthermore, nonpigmentedctpAΔ conidia elicited much stronger immune responses from the infected invertebrate hostGalleria mellonellathan the pigmentedctpAΔ or wild-type conidia. Such enhancement in elicitingGalleriaimmune responses was independent of thectpAΔ conidial viability, as previously observed for the DHN melanin mutants. Taken together, our findings indicate that both copper homeostasis and developmental regulators control melanin biosynthesis, which affects conidial surface properties that shape the interaction between this pathogen and its host.

scholarly journals Dynamic Behavior of the trans-Golgi Network in Root Tissues of Arabidopsis Revealed by Super-Resolution Live Imaging

2014 ◽  
Vol 55 (4) ◽  
pp. 694-703 ◽  
Author(s):  
Tomohiro Uemura ◽  
Yasuyuki Suda ◽  
Takashi Ueda ◽  
Akihiko Nakano
Keyword(s):  
Dynamic Behavior ◽  
Super Resolution ◽  
Live Imaging ◽  
Trans Golgi Network ◽  
Root Tissues ◽  
Golgi Network

scholarly journals Lead Exposure Induced Copper Clearance Disorder of Blood-CSF Barrier

2020 ◽  
Author(s):  
Bin He ◽  
Liyuan Wang ◽  
Shuang Li ◽  
Fuyuan Cao ◽  
Lei Wu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Choroid Plexus ◽  
Lead Exposure ◽  
Regulatory Function ◽  
Copper Level ◽  
Mitochondrial Morphology ◽  
Normal Brain ◽  
Sprague Dawley ◽  
Copper Transporter ◽  
The Brain

Abstract Lead is a heavy metal commonly found in the environment with known neurotoxicity, hematological and other toxicities. It has been found that lead exposure can disturb partial metal regulatory function in the blood-CSF barrier (BCB). Copper, which play an important role in maintaining normal brain function, can accumulate in brain after lead exposure. The studies of Alzheimer's disease (AD) indicated that abnormal copper homeostasis in cerebrospinal fluid (CSF) may be involved in the pathogenesis. However, the mechanism of copper disturbance in the brain caused by lead is still unknown. This study was designed to investigate copper clearance by the BCB in central nervous system after lead exposure, with focus on copper transporter protein CTR1/ATP7A. Inductively coupled plasma mass spectrometry (ICP-MS) and principal component analysis (PCA) were used to identify the changes of heavy metal level in hippocampus and CSF after lead exposure. It was found that the change in copper level was most pronounced in the brain between 3 to 12 weeks post lead exposure. Ventriculo-cisternal (VC) perfusion in Sprague Dawley (SD) rat suggested that the ability of BCB to deliver copper from the CSF to blood was decreased after lead exposure. Confocal microscope showed evidence of the presence of excess copper in the choroid plexus cells leading to CTR1/ATP7A shifting toward the apical microvilli facing the CSF after lead exposure. Finally, transmission electron microscopy (TEM) was used for observation of the microstructure of choroid plexus showed altered mitochondrial morphology with decreased microvilli after lead exposure. Our data suggested that lead exposure may alter BCB cellular microscopic structure and its copper transport, clearance function that might further cause brain injury.

IV. Wilson’s disease and Menkes disease

1999 ◽  
Vol 276 (2) ◽  
pp. G311-G314 ◽  
Author(s):  
Mark Schaefer ◽  
Jonathan D. Gitlin
Keyword(s):  
Wilson’S Disease ◽  
Clinical Presentation ◽  
Genetic Disorders ◽  
Copper Metabolism ◽  
Menkes Disease ◽  
Wilson's Disease ◽  
Inherited Disorders ◽  
Specific Expression ◽  
Cellular Copper ◽  
Golgi Network

Copper is an essential transition metal that permits the facile transfer of electrons in a series of critical biochemical pathways. Menkes disease and Wilson’s disease are inherited disorders of copper metabolism resulting from the absence or dysfunction of homologous copper-transporting ATPases that reside in the trans-Golgi network of all cells. Despite striking differences in the clinical presentation of these two diseases, the respective ATPases function in precisely the same manner within the cell and the unique clinical features of each disease are entirely the result of the tissue-specific expression of each protein. Elucidation of the basic defect in these rare genetic disorders has provided a valuable heuristic paradigm for understanding the mechanisms of cellular copper homeostasis.

Sign in / Sign up

Export Citation Format

Share Document