Gliarin and macrolin, two novel intermediate filament proteins specifically expressed in sets and subsets of glial cells in leech central nervous system.
Using monoclonal antibodies, we have identified two novel intermediate filament (IF) proteins, Gliarin and Macrolin, which are specifically expressed in the central nervous system of an invertebrate. The two proteins both contain the coiled-coil rod domain typical of the superfamily of IF proteins flanked by unique N- and C-terminal domains. Gliarin was found in all glial cells including macro- and microglial cells, whereas Macrolin was expressed in only a single pair of giant connective glial cells. The identification of Macrolin and Gliarin together with the characterization of the strictly neuronal IF protein Filarin in leech central nervous system demonstrate that multiple neuron- and glial-specific IFs are not unique to the vertebrate nervous system but are also found in invertebrates. Interestingly, phylogenetic analysis based on maximum parsimony indicated that the presence of neuron- and glial cell-specific IFs in coelomate protostomes as well as in vertebrates is not of monophyletic origin, but rather represents convergent evolution and appears to have arisen independently.
Xu
Y
Y
Department of Zoology and Genetics, 3156 Molecular Biology Building, Iowa State University, Ames, Iowa 50011, USA.
Bolton
B
B
Zipser
B
B
Jellies
J
J
Johansen
K M
KM
Johansen
J
J
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002490:Central Nervous System / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D007381:Intermediate Filament Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D007865:Leeches / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D010802:Phylogeny; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C095386:filarin protein, Haemopis marmorata; C122018:gliarin protein, Hirudo medicinalis; C122017:macrolin protein, Hirudo medicinalis