Diacylglycerol kinase beta accumulates on the perisynaptic site of medium spiny neurons in the striatum.

Full Abstract

Following activation of Gq protein-coupled receptors, phospholipase C yields a pair of second messengers, i.e. diacylglycerol (DAG) and inositol 1,4,5-trisphosphate. The former activates protein kinase C and the latter mobilizes Ca(2+) from intracellular store. DAG kinase (DGK) then phosphorylates DAG to produce another second messenger (phosphatidic acid). Of 10 mammalian DGK isozymes, DGKbeta is expressed in dopaminergic projection fields with the highest level in the striatum and its particular splice variant is differentially expressed in patients with bipolar disorder. To gain molecular anatomical evidence for its signaling role, we investigated the cellular expression and subcellular localization of DGKbeta in the striatum of rat brain. DGKbeta was expressed in medium spiny neurons constituting the striatonigral and striatopallidal pathways, whereas striatal interneurons were below the detection threshold. DGKbeta was distributed in somatodendritic elements of medium spiny neurons and localized in association with the smooth endoplasmic reticulum and plasma membrane or in the narrow cytoplasmic space between them. In particular, DGKbeta exhibited dense accumulation at perisynaptic sites on dendritic spines forming asymmetrical synapses. The characteristic anatomical localization was consistent with exclusive enrichment of DGKbeta in the microsomal and postsynaptic density fractions. Intriguingly, DGKbeta was very similar in immunohistochemical and immunochemical distribution to Gq-coupled receptors, such as metabotropic glutamate receptors 1 and 5, and also to other downstream molecules involving DAG metabolism, such as phospholipase C beta and DAG lipase. These findings suggest that abundant DGKbeta is provided to perisynaptic sites of medium spiny neurons so that it can effectively produce phosphatidic acid upon activation of Gq-coupled receptors and modulate the cellular state of striatal output neurons.

Author information

Author/s: Hozumi, Yasukazu (Y); Fukaya, Masahiro (M); Adachi, Naoko (N); Saito, Naoaki (N); Otani, Koichi (K); Kondo, Hisatake (H); Watanabe, Masahiko (M); Goto, Kaoru (K);

Affiliation: Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iida-nishi 2-2-2, Yamagata 990-9585, Japan. yahodumi(-atsign-)med.id.yamagata-u.ac.jp

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: The European journal of neuroscience (Eur J Neurosci), published in France. (Language: eng)

Reference: 2008-Dec; vol 28 (issue 12) : pp 2409-22

Dates: Created 2008/12/17; Completed 2009/02/03;

PMID: 19087171, status: MEDLINE (last retrieved date: 2/18/2009)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.