Metabolic and Molecular Bases of Menkes Disease and Occipital Horn Syndrome

1998 ◽  
Vol 1 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Stephen G. Kaler
Keyword(s):  
Major Gene ◽  
Premature Death ◽  
Menkes Disease ◽  
Pedigree Analysis ◽  
Copper Transport ◽  
Gene Deletions ◽  
Molecular Defects ◽  
P Type ◽  
Golgi Network ◽  
Occipital Horn

Menkes disease and occipital horn syndrome (OHS) are related disorders of copper transport that involve abnormal neurodevelopment, connective tissue problems, and often premature death. Location of the gene responsible for these conditions on the X chromosome was indicated by pedigree analysis from the time of these syndromes' earliest descriptions. Characterization of an affected female with an X-autosomal translocation was used to identify the Menkes/OHS gene, which encodes a highly evolutionarily conserved, copper-transporting P-type ATPase. The gene normally is expressed in nearly all human tissues, and it localizes to the trans-Golgi network of cells. However, in over 70% of Menkes and OHS patients studied, expression of this gene has been demonstrated to be abnormal. Major gene deletions detectable by Southern blotting account for 15–20% of patients, and an interesting spectrum of other mutations is evident among 58 families whose precise molecular defects have been reported as of this writing. The center region of the gene seems particularly prone to mutation, and those that influence mRNA processing and splicing appear to be relatively common. Further advances in understanding the molecular and cell biological mechanisms involved in normal copper transport may ultimately yield new and better approaches to the management of these disorders.

Inherited diseases of copper metabolism: Wilson’s disease and Menkes’ disease

2020 ◽  
pp. 2115-2120
Author(s):  
Michael L. Schilsky ◽  
Pramod K. Mistry
Keyword(s):  
Liver Disease ◽  
Fulminant Hepatic Failure ◽  
Hepatic Failure ◽  
Wilson’S Disease ◽  
Menkes Disease ◽  
Wilson's Disease ◽  
Copper Transport ◽  
Loss Of Function ◽  
Copper Excretion ◽  
P Type

Copper is an essential metal that is an important cofactor for many proteins and enzymes. Two related genetic defects in copper transport have been described, each with distinct phenotypes. Wilson’s disease—an uncommon disorder (1 in 30 000) caused by autosomal recessive loss-of-function mutations in a metal-transporting P-type ATPase (ATP7B) that result in defective copper excretion into bile and hence copper toxicity. Typical presentation is in the second and third decade of life with liver disease (ranging from asymptomatic to acute fulminant hepatic failure or chronic end-stage liver disease) or neurological or psychiatric disorder (dystonia, dysarthria, parkinsonian tremor, movement disorder, a spectrum of psychiatric ailments). While no single biochemical test or clinical finding is sufficient for establishing the diagnosis, typical findings include low serum ceruloplasmin, high urinary copper excretion, and elevated liver copper content. Corneal Kayser–Fleischer rings may be seen. Treatment is with copper chelating agents and zinc. Liver transplantation is required for fulminant hepatic failure and decompensated liver disease unresponsive to medical therapy. Menkes’ disease—a rare disorder (1 in 300 000) caused by X-linked loss-of-function mutations in a P-type ATPase homologous to ATP7B (ATP7A) that result in defective copper transport across intestine, placenta, and brain and hence cellular copper deficiency. Clinical presentation is in infancy with facial dimorphism, connective tissue disorder, hypopigmentation, abnormal hair, seizures, and failure to thrive, usually followed by death by age 3 years (although some variants with a milder phenotype result from milder mutations, e.g. occipital horn syndrome). Treatment, which is only effective when presymptomatic diagnosis is made in a sibling after florid presentation in a previous affected sibling, is with intravenous copper histidine.

scholarly journals Expression of Menkes disease gene in mammary carcinoma cells

1997 ◽  
Vol 328 (1) ◽  
pp. 237-243 ◽  
Author(s):  
M. Leigh ACKLAND ◽  
E. Jean CORNISH ◽  
A. Jenny PAYNTER ◽  
Andrew GRIMES ◽  
Agnes MICHALCZYK ◽  
...  
Keyword(s):  
Blot Analysis ◽  
Northern Blot Analysis ◽  
Menkes Disease ◽  
Copper Transport ◽  
Carcinoma Cells ◽  
Western Blots ◽  
Human Disorders ◽  
Mammary Carcinoma Cells ◽  
P Type ◽  
Punctate Staining

Two P-type ATPases, MNK and WND were recently shown to be defective in the human disorders of copper transport, Menkes disease and Wilson disease respectively. These proteins are important in copper homeostasis but their full physiological function has not been established. This study uses the human breast carcinoma line, PMC42, to investigate copper transport in the mammary gland. Northern blot analysis indicated that both MNK and WND mRNA are expressed in these cells. Western blot analysis with an MNK-specific antibody demonstrated a band of approx. 178 kDa, close to the expected size of 163 kDa. Treatment of PMC42 cells with lactational hormones (oestrogen and progesterone for 3 days followed by dexamethasone, insulin and prolactin for a further 3 days) did not produce an obvious increase in MNK expression as measured by Northern and Western blots. By using indirect immunofluorescence with the MNK antibody, the intracellular distribution of MNK was found to be predominantly perinuclear, consistent with Golgi localization. Punctate staining was also seen in a smaller proportion of cells, suggesting that some MNK is associated with endosomes. Treatment of PMC42 cells with lactational hormones increased the intensity of the perinuclear and punctate fluorescence. Exposure of cells to 100 mM copper resulted in the dispersion of the fluorescence towards the periphery of the cell. The results suggest a role for MNK in the secretion of copper into milk and that PMC42 cells are a valuable model for investigating the detailed cellular function of MNK and WND.

scholarly journals Menkes Protein Contributes to the Function of Peptidylglycine α-Amidating Monooxygenase

Endocrinology ◽  
2003 ◽  
Vol 144 (1) ◽  
pp. 188-200 ◽  
Author(s):  
Tami C. Steveson ◽  
Giuseppe D. Ciccotosto ◽  
Xin-Ming Ma ◽  
Gregory P. Mueller ◽  
Richard E. Mains ◽  
...  
Keyword(s):  
Biological Effects ◽  
Menkes Disease ◽  
Copper Zinc Superoxide Dismutase ◽  
Protein Levels ◽  
Brain Extracts ◽  
Copper Zinc ◽  
Menkes Protein ◽  
P Type ◽  
Golgi Network ◽  
Rats And Mice

Abstract Menkes protein (ATP7A) is a P-type ATPase involved in copper uptake and homeostasis. Disturbed copper homeostasis occurs in patients with Menkes disease, an X-linked disorder characterized by mental retardation, neurodegeneration, connective tissue disorders, and early childhood death. Mutations in ATP7A result in malfunction of copper-requiring enzymes, such as tyrosinase and copper/zinc superoxide dismutase. The first step of the two-step amidation reaction carried out by peptidylglycine α-amidating monooxygenase (PAM) also requires copper. We used tissue from wild-type rats and mice and an ATP7A-specific antibody to determine that ATP7A is expressed at high levels in tissues expressing high levels of PAM. ATP7A is largely localized to the trans Golgi network in pituitary endocrine cells. The Atp7a mouse, bearing a mutation in the Atp7a gene, is an excellent model system for examining the consequences of ATP7A malfunction. Despite normal levels of PAM protein, levels of several amidated peptides were reduced in pituitary and brain extracts of Atp7a mice, demonstrating that PAM function is compromised when ATP7A is inactive. Based on these results, we conclude that a reduction in the ability of PAM to produce bioactive end-products involved in neuronal growth and development could contribute to many of the biological effects associated with Menkes disease.

Inherited diseases of copper metabolism: Wilson’s disease and Menkes’ disease

2010 ◽  
pp. 1688-1693
Author(s):  
Michael L. Schilsky ◽  
Pramod K. Mistry
Keyword(s):  
Autosomal Recessive ◽  
Copper Metabolism ◽  
Menkes Disease ◽  
Wilson's Disease ◽  
Copper Transport ◽  
Genetic Defects ◽  
Loss Of Function ◽  
Essential Metal ◽  
Inherited Diseases ◽  
P Type

Copper is an essential metal that is an important cofactor for many proteins and enzymes. Two related genetic defects in copper transport have been described. An uncommon disorder (1 in 30 000) caused by autosomal recessive loss of function mutations in a metal-transporting P-type ATPase (...

Disorders of Copper and Iron Metabolism

2016 ◽  
Author(s):  
Jean-Marc Trocello ◽  
France Woimant
Keyword(s):  
Metabolic Pathways ◽  
Menkes Disease ◽  
Motor Neuropathy ◽  
Brain Iron ◽  
Critical Function ◽  
Excess Iron ◽  
Biochemical Pathways ◽  
Genetic Abnormalities ◽  
P Type ◽  
Occipital Horn

Both copper and iron are essential metals that have a critical function in a series of biochemical pathways. This chapter describes the disorders associated with genetic abnormalities in copper and iron metabolic pathways and their manifestations in adult patients. Mutations in the genes of the copper transporting P-type ATPases, ATP7A and ATP7B are associated with Wilson disease, Menkes disease, occipital horn syndrome and ATP7A-related distal motor neuropathy. Neurodegeneration with brain iron accumulation (NBIA) is a group of disorders characterized by excess iron deposition in globus pallidus, substantia nigra pars reticulata, striata and cerebellar dentate nuclei. Several genes associated with NBIA have been identified.

scholarly journals Multiple di-leucines in the ATP7A copper transporter are required for retrograde trafficking to the trans-Golgi network

Metallomics ◽  
2016 ◽  
Vol 8 (9) ◽  
pp. 993-1001 ◽  
Author(s):  
Sha Zhu ◽  
Vinit Shanbhag ◽  
Victoria L. Hodgkinson ◽  
Michael J. Petris
Keyword(s):  
Copper Metabolism ◽  
Menkes Disease ◽  
Copper Transporter ◽  
Retrograde Trafficking ◽  
Trans Golgi Network ◽  
P Type ◽  
Golgi Network

The ATP7A protein is a ubiquitous copper-transporting P-type ATPase that is mutated in the lethal pediatric disorder of copper metabolism, Menkes disease.

scholarly journals Cofilin recruits F-actin to SPCA1 and promotes Ca2+-mediated secretory cargo sorting

2014 ◽  
Vol 206 (5) ◽  
pp. 635-654 ◽  
Author(s):  
Christine Kienzle ◽  
Nirakar Basnet ◽  
Alvaro H. Crevenna ◽  
Gisela Beck ◽  
Bianca Habermann ◽  
...  
Keyword(s):  
Secretory Pathway ◽  
Nitrilotriacetic Acid ◽  
Calcium Atpase ◽  
Secretory Proteins ◽  
Dependent Manner ◽  
Agarose Beads ◽  
P Type ◽  
Golgi Network ◽  
Phosphorylation Domain ◽  
Cargo Sorting

The actin filament severing protein cofilin-1 (CFL-1) is required for actin and P-type ATPase secretory pathway calcium ATPase (SPCA)-dependent sorting of secretory proteins at the trans-Golgi network (TGN). How these proteins interact and activate the pump to facilitate cargo sorting, however, is not known. We used purified proteins to assess interaction of the cytoplasmic domains of SPCA1 with actin and CFL-1. A 132–amino acid portion of the SPCA1 phosphorylation domain (P-domain) interacted with actin in a CFL-1–dependent manner. This domain, coupled to nickel nitrilotriacetic acid (Ni-NTA) agarose beads, specifically recruited F-actin in the presence of CFL-1 and, when expressed in HeLa cells, inhibited Ca2+ entry into the TGN and secretory cargo sorting. Mutagenesis of four amino acids in SPCA1 that represent the CFL-1 binding site also affected Ca2+ import into the TGN and secretory cargo sorting. Altogether, our findings reveal the mechanism of CFL-1–dependent recruitment of actin to SPCA1 and the significance of this interaction for Ca2+ influx and secretory cargo sorting.

Identification of a di-leucine motif within the C terminus domain of the Menkes disease protein that mediates endocytosis from the plasma membrane

1999 ◽  
Vol 112 (11) ◽  
pp. 1721-1732 ◽  
Author(s):  
M.J. Francis ◽  
E.E. Jones ◽  
E.R. Levy ◽  
R.L. Martin ◽  
S. Ponnambalam ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Transmembrane Domain ◽  
Menkes Disease ◽  
Cytoplasmic Domain ◽  
Endocytic Pathway ◽  
Site Directed Mutagenesis ◽  
Trans Golgi Network ◽  
C Terminus ◽  
Golgi Network

The protein encoded by the Menkes disease gene (MNK) is localised to the Golgi apparatus and cycles between the trans-Golgi network and the plasma membrane in cultured cells on addition and removal of copper to the growth medium. This suggests that MNK protein contains active signals that are involved in the retention of the protein to the trans-Golgi network and retrieval of the protein from the plasma membrane. Previous studies have identified a signal involved in Golgi retention within transmembrane domain 3 of MNK. To identify a motif sufficient for retrieval of MNK from the plasma membrane, we analysed the cytoplasmic domain, downstream of transmembrane domain 7 and 8. Chimeric constructs containing this cytoplasmic domain fused to the reporter molecule CD8 localised the retrieval signal(s) to 62 amino acids at the C terminus. Further studies were performed on putative internalisation motifs, using site-directed mutagenesis, protein expression, chemical treatment and immunofluorescence. We observed that a di-leucine motif (L1487L1488) was essential for rapid internalisation of chimeric CD8 proteins and the full-length Menkes cDNA from the plasma membrane. We suggest that this motif mediates the retrieval of MNK from the plasma membrane into the endocytic pathway, via the recycling endosomes, but is not sufficient on its own to return the protein to the Golgi apparatus. These studies provide a basis with which to identify other motifs important in the sorting and delivery of MNK from the plasma membrane to the Golgi apparatus.

Sign in / Sign up

Export Citation Format

Share Document