Evolution of myelin proteolipid proteins: gene duplication in teleosts and expression pattern divergence.
The coevolution of neurons and their supporting glia to the highly specialized axon-myelin unit included the recruitment of proteolipids as neuronal glycoproteins (DMbeta, DMgamma) or myelin proteins (DMalpha/PLP/DM20). Consistent with a genome duplication at the root of teleosts, we identified three proteolipid pairs in zebrafish, termed DMalpha1 and DMalpha2, DMbeta1 and DMbeta2, DMgamma1 and DMgamma2. The paralogous amino acid sequences diverged remarkably after gene duplication, indicating functional specialization. Each proteolipid has adopted a distinct spatio-temporal expression pattern in neural progenitors, neurons, and in glia. DMalpha2, the closest homolog to mammalian PLP/DM20, is coexpressed with P0 in oligodendrocytes and upregulated after optic nerve lesion. DMgamma2 is expressed in multipotential stem cells, and the other four proteolipids are confined to subsets of CNS neurons. Comparing protein sequences and gene structures from birds, teleosts, one urochordate species, and four invertebrates, we have reconstructed major steps in the evolution of proteolipids.
Schweitzer
Jörn
J
Zentrum fuer Molekulare Neurobiologie, University of Hamburg, D-20251 Hamburg, Germany.
Becker
Thomas
T
Schachner
Melitta
M
Nave
Klaus-Armin
KA
Werner
Hauke
H
D000595:Amino Acid Sequence; D000818:Animals; D016384:Consensus Sequence; D019143:Evolution, Molecular; D005399:Fishes / Q000235:genetics*; D020440:Gene Duplication; D005786:Gene Expression Regulation; D014644:Genetic Variation; D016678:Genome; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018991:Myelin Proteolipid Protein / Q000737:chemistry / Q000235:genetics*; D011487:Protein Conformation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000737:chemistry / Q000235:genetics
D018991:Myelin Proteolipid Protein; D029961:Zebrafish Proteins