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Evolutionary origin of cholinergic macromolecules and thyroglobulin

Mori, Nozomu and Itoh, Nobuyuki and Salvaterra, Paul M. (1987) Evolutionary origin of cholinergic macromolecules and thyroglobulin. Proceedings of the National Academy of Sciences of the United States of America, 84 (9). pp. 2813-2817. ISSN 0027-8424. PMCID PMC304749. doi:10.1073/pnas.84.9.2813.

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We have compared the amino acid sequences of proteins that are involved in acetylcholine (AcCho) metabolism and cholinergic neurotransmission: choline acetyltransferase (ChoAcTase), acetylcholinesterase (AcChoEase), and a neuronal subunit of nicotinic AcCho receptor (AcChoR). A comparison of Drosophila ChoAcTase and rat neuronal subunit of AcChoR shows a limited segmental type homology, which may suggest a similar acetylcholine binding site in the two proteins evolving by convergence. We note a global homology of 21-44% identity between Drosophila ChoAcTase and Torpedo AcChoEase. Six homologous segments of 40-60 amino acids cover 38% and 54% of the sequences, raising the possibility of a common evolutionary origin. We also note that mammalian thyroglobulin (TG), the precursor for thyroid hormones, contains an AcChoEase-like sequence at its carboxyl end. This homology raises the possibility that the gene for TG has evolved by gene fusion or condensation (i.e., recruiting a preexisting redundant copy of a gene for AcChoEase during vertebrate evolution). Our results demonstrate that the record of evolutionary history for nervous system proteins can be read across the boundaries of separation between vertebrates and invertebrates. They also provide molecular evidence for the common evolutionary origins of the nervous and endocrine systems in vertebrates -- both evolving to make intercellular communication possible.

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Additional Information:© 1987 by the National Academy of Sciences. Contributed by Susumu Ohno, November 6, 1986. We thank Drs. S. Ohno and T. Okada for advice and encouragement; Drs. J. Ono, K. Ikeda, and J. Singer-Sam for discussions; and Dr. A. Riggs for support. This work was supported by National Institutes of Health Grant NS19482. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
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Subject Keywords:choline acetyltransferase; acetylcholinesterase; acetylcholine receptor; gene recruitment; evolution
Issue or Number:9
PubMed Central ID:PMC304749
Record Number:CaltechAUTHORS:MORpnas87
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9271
Deposited By: Tony Diaz
Deposited On:05 Dec 2007
Last Modified:08 Nov 2021 20:57

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