4b4y

Publication Abstract from PubMed

Neuroglobins, previously thought to be restricted to vertebrate neurons, were detected in the brain of a photosymbiotic acoel, Symsagittifera roscoffensis, and in neuro-sensory cells of the jellyfish Clytia hemisphaerica. For the neuroglobin of S. roscoffensis, a member of a lineage that originated either at the base of the bilateria or of the deuterostome clade, we report the ligand-binding properties, crystal structure at 2.3 A and brain immuno-cytochemical pattern. We also describe in situ hybridizations of two neuroglobins specifically expressed in differentiating nematocytes (neuro-sensory cells) and in statocytes (ciliated mechano-sensory cells) of C. hemisphaerica, a member of the early-branching animal phylum cnidaria. In silico searches using these neuroglobins as queries revealed the presence of previously unidentified neuroglobin-like sequences in most metazoan lineages. Since neural systems are almost ubiquitous in metazoa, the constitutive expression of neuroglobin-like proteins strongly supports the notion of an intimate association of neuroglobins with the evolution of animal neural systems and hints at the preservation of a vitally important function. Neuroglobins were probably recruited in the first proto-neurons in early metazoans from globin precursors. Neuroglobins were identified in choanoflagellates, sponges and placozoans, and were conserved during nervous system evolution. Since the origin of neuroglobins predates the other metazoan globins, it is likely that neuroglobin gene duplication followed by co-option and subfunctionalization led to the emergence of globin families in protostomes and deuterostomes (i.e convergent evolution).

Neuroglobins: pivotal proteins associated with emerging neural systems and precursors of metazoan globin diversity.,Lechauve C, Jager M, Laguerre L, Kiger L, Correc G, Leroux C, Vinogradov S, Czjzek M, Marden MC, Bailly X J Biol Chem. 2013 Jan 3. PMID:23288852^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.