PMID- 10484781
OWN - NLM
STAT- MEDLINE
DCOM- 19991216
LR  - 20191210
IS  - 0964-6906 (Print)
IS  - 0964-6906 (Linking)
VI  - 8
IP  - 11
DP  - 1999 Oct
TI  - The Menkes protein (ATP7A; MNK) cycles via the plasma membrane both in basal and 
      elevated extracellular copper using a C-terminal di-leucine endocytic signal.
PG  - 2107-15
AB  - Menkes disease is an X-linked recessive copper deficiency disorder caused by
      mutations in the ATP7A ( MNK ) gene which encodes a copper transporting P-type
      ATPase (MNK). MNK is normally localized pre- dominantly in the trans -Golgi
      network (TGN); however, when cells are exposed to excessive copper it is rapidly 
      relocalized to the plasma membrane where it functions in copper efflux. In this
      study, the c-myc epitope was introduced within the loop connecting the first and 
      second transmembrane regions of MNK. This myc epitope allowed detection of the
      protein at the surface of living cells and provided the first experimental
      evidence supporting the common topological model. In cells stably expressing the 
      tagged MNK protein (MNK-tag), extracellular antibodies were internalized to the
      perinuclear region, indicating that MNK-tag at the TGN constitutively cycles via 
      the plasma membrane in basal copper conditions. Under elevated copper conditions,
      MNK-tag was recruited to the plasma membrane; however, internalization of MNK-tag
      was not inhibited and the protein continued to recycle through cyto- plasmic
      membrane compartments. These findings suggest that copper stimulates exocytic
      movement of MNK to the plasma membrane rather than reducing MNK retrieval and
      indicate that MNK may remove copper from the cytoplasm by transporting copper
      into the vesicles through which it cycles. Newly internalized MNK-tag and
      transferrin were found to co-localize, suggesting that MNK-tag follows a
      clathrin-coated pit/endosomal pathway into cells. Mutation of the di-leucine,
      L1487 L1488, prevented uptake of anti-myc antibodies in both basal and elevated
      copper conditions, thereby identifying this sequence as an endocytic signal for
      MNK. Analysis of the effects of the di-leucine mutation in elevated copper
      provided further support for copper-stimulated exocytic movement of MNK from the 
      TGN to the plasma membrane.
FAU - Petris, M J
AU  - Petris MJ
AD  - The Murdoch Institute, Royal Children's Hospital, Parkville 3052, Australia.
FAU - Mercer, J F
AU  - Mercer JF
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Hum Mol Genet
JT  - Human molecular genetics
JID - 9208958
RN  - 0 (Antibodies)
RN  - 0 (Carrier Proteins)
RN  - 0 (Cation Transport Proteins)
RN  - 0 (Culture Media, Serum-Free)
RN  - 0 (Epitopes)
RN  - 0 (Proto-Oncogene Proteins c-myc)
RN  - 0 (Recombinant Fusion Proteins)
RN  - 0 (Transferrin)
RN  - 789U1901C5 (Copper)
RN  - EC 3.6.1.- (Adenosine Triphosphatases)
RN  - EC 7.2.2.8 (ATP7A protein, human)
RN  - EC 7.2.2.8 (Copper-Transporting ATPases)
RN  - GMW67QNF9C (Leucine)
SB  - IM
MH  - Adenosine Triphosphatases/chemistry/genetics/immunology/*metabolism
MH  - Animals
MH  - Antibodies/metabolism
MH  - CHO Cells/drug effects/metabolism
MH  - Carrier Proteins/chemistry/genetics/immunology/*metabolism
MH  - *Cation Transport Proteins
MH  - Cell Membrane/*metabolism
MH  - Cells, Cultured
MH  - Colony-Forming Units Assay
MH  - Copper/*metabolism/toxicity
MH  - Copper-Transporting ATPases
MH  - Cricetinae
MH  - Cricetulus
MH  - Culture Media, Serum-Free
MH  - Drug Resistance/genetics
MH  - Endocytosis/*physiology
MH  - Epitopes/analysis/immunology
MH  - Exocytosis
MH  - Humans
MH  - Ion Transport
MH  - Leucine/*chemistry
MH  - Menkes Kinky Hair Syndrome/*enzymology/genetics
MH  - Organelles/metabolism
MH  - *Protein Structure, Tertiary
MH  - Proto-Oncogene Proteins c-myc/immunology
MH  - Recombinant Fusion Proteins/metabolism
MH  - Transfection
MH  - Transferrin/metabolism
EDAT- 1999/09/15 00:00
MHDA- 1999/09/15 00:01
CRDT- 1999/09/15 00:00
PHST- 1999/09/15 00:00 [pubmed]
PHST- 1999/09/15 00:01 [medline]
PHST- 1999/09/15 00:00 [entrez]
AID - ddc241 [pii]
AID - 10.1093/hmg/8.11.2107 [doi]
PST - ppublish
SO  - Hum Mol Genet. 1999 Oct;8(11):2107-15. doi: 10.1093/hmg/8.11.2107.