Bral1, a brain-specific link protein, colocalizing with the versican V2 isoform at the nodes of Ranvier in developing and adult mouse central nervous systems.
Bral1, a brain-specific hyaluronan-binding protein, has been cloned recently. To gain insight into the role of Bral1, we generated a specific antibody against this protein. We have examined the detailed localization pattern of Bral1 protein and compared it with that of other members of the lectican proteoglycan family, such as brevican and versican, with which Bral1 is predicted to interact. The immunoreactivity of Bral1 antibody was predominantly observed in myelinated fiber tracts in the adult brain and could be detected at P20 in the white matter of the developing cerebellum, suggesting that expression starts when axonal myelination takes place. Furthermore, immunostaining demonstrated that Bral1 colocalized with the versican V2 isoform at the nodes of Ranvier. The present data suggest that Bral1 may play a pivotal role in the formation of the hyaluronan-associated matrix in the CNS that facilitates neuronal conduction by forming an ion diffusion barrier at the nodes.
Oohashi
Toshitaka
T
Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine and Dentistry, Okayama, 700-8558, Japan. oohashi@cc.okyama-u.ac.jp
Hirakawa
Satoshi
S
Bekku
Yoko
Y
Rauch
Uwe
U
Zimmermann
Dieter R
DR
Su
Wei-Dong
WD
Ohtsuka
Aiji
A
Murakami
Takuro
T
Ninomiya
Yoshifumi
Y
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D002490:Central Nervous System / Q000737:chemistry* / Q000166:cytology / Q000254:growth & development*; D011508:Chondroitin Sulfate Proteoglycans / Q000032:analysis* / Q000737:chemistry; D005109:Extracellular Matrix / Q000737:chemistry / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D006820:Hyaluronic Acid / Q000378:metabolism; D007150:Immunohistochemistry; D007536:Isomerism; D037181:Lectins, C-Type; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000737:chemistry / Q000502:physiology; D010446:Peptide Fragments / Q000276:immunology; D011509:Proteoglycans / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D011901:Ranvier's Nodes / Q000737:chemistry*; D053675:Versicans; D000099249:Proteoglycan Link Protein
D000906:Antibodies; D011508:Chondroitin Sulfate Proteoglycans; D006820:Hyaluronic Acid; D037181:Lectins, C-Type; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011509:Proteoglycans; D053675:Versicans; C485934:Hapln2 protein, mouse; D000099249:Proteoglycan Link Protein; C508323:Vcan protein, mouse