title: MLC1: a novel protein in distal astroglial processes.
abstract: Megaloencephalic leukoencephalopathy with subcortical cysts (MLC) is a progressive cerebral white matter disease in children caused by mutations in the MLC1 gene. This disease is histopathologically characterized by myelin splitting and intramyelinic vacuole formation. MLC1 encodes a novel protein, MLC1, which is mainly expressed in the brain and leukocytes. The function is unknown, although a transport function has been suggested. In this article, we provide experimental data addressing the membrane topology and cellular localization of MLC1. We show that MLC1 contains an even number of transmembrane domains, supporting the possible transport function of MLC1. We demonstrate that MLC1 is specifically expressed in distal astroglial processes in perivascular, subependymal, and subpial regions. This localization suggests a role for MLC1 in a transport process across the blood-brain and brain-cerebrospinal fluid barriers. Astrocyte functions have long been debated. It is becoming increasingly clear that these cells are of fundamental importance in maintaining the structural and functional integrity of neural tissue. Elucidation of the function of MLC1 will contribute to a better understanding of not only the pathophysiology of the disease, but also the role of astrocytes in normal neural tissue.
authors.affiliation: Department of Pediatrics/Child Neurology, VU University Medical Center, Amsterdam, The Netherlands. boor@cncr.vu.nl
authors.forename: P K Ilja
authors.initials: PK
authors.lastname: Boor
authors.forename: Koen
authors.initials: K
authors.lastname: de Groot
authors.forename: Quinten
authors.initials: Q
authors.lastname: Waisfisz
authors.forename: Wouter
authors.initials: W
authors.lastname: Kamphorst
authors.forename: Cees B M
authors.initials: CB
authors.lastname: Oudejans
authors.forename: James M
authors.initials: JM
authors.lastname: Powers
authors.forename: Jan C
authors.initials: JC
authors.lastname: Pronk
authors.forename: Gert C
authors.initials: GC
authors.lastname: Scheper
authors.forename: Marjo S
authors.initials: MS
authors.lastname: van der Knaap
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001253:Astrocytes / Q000378:metabolism*; D015153:Blotting, Western / Q000379:methods; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D002645:Chickens; D003001:Cloning, Molecular / Q000379:methods; D005434:Flow Cytometry / Q000379:methods; D005455:Fluorescent Antibody Technique / Q000379:methods; D005786:Gene Expression Regulation / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D016415:Sequence Alignment; D023741:Takifugu; D014162:Transfection / Q000379:methods; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D005904:Glial Fibrillary Acidic Protein; D008565:Membrane Proteins; D012333:RNA, Messenger; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C425069:MLC1 protein, human; C498927:Mlc1 protein, mouse