The dopamine transporter (DAT) has been identified as the principal brain receptor site previoiusly correlated with the rewarding and euphoric properties of cocaine. Euphoric responses to rapid administration of cocaine can be much more prominent than those that follow slower rates of administration. In previous FYs, investigators in this Branch have found that activators of protein kinase C (PKC) modulate dopamine transport in transiently-expressing COS cells. In this FY, we have followed previous observations that identified DAT as a phosphoprotein, and identified predominant serine phosphoacceptor sites in phosphoamino acid analyses. Studies of site directed mutants in potential phosphoacceptor sites identify no single residue as a sole site. These data increase evidence that PKC activation enhances levels of DAT phosphorylation at multiple serines, and makes phosphorylation an increasingly-strong candidate mechanism for rapid adaptations in dopaminergic systems relevant to cocaine-induced euphoria.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Intramural Research (Z01)
Project #
1Z01DA000159-04
Application #
6103869
Study Section
Special Emphasis Panel (MNB)
Program Officer
Wetherington, Cora Lee
Project Start
Project End
Budget Start
Budget End
Support Year
4
Fiscal Year
1998
Total Cost
Indirect Cost
Name
National Institute on Drug Abuse
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Lin, Zhicheng; Uhl, George R (2005) Proline mutations induce negative-dosage effects on uptake velocity of the dopamine transporter. J Neurochem 94:276-87
Dohi, Toshihiro; Kitayama, Shigeo; Morioka, Norimitsu et al. (2004) Regulation of dopamine and MPP+ transport by catecholamine transporters. Nihon Shinkei Seishin Yakurigaku Zasshi 24:43-7
Lin, Zhicheng; Zhang, Ping-Wu; Zhu, Xuguang et al. (2003) Phosphatidylinositol 3-kinase, protein kinase C, and MEK1/2 kinase regulation of dopamine transporters (DAT) require N-terminal DAT phosphoacceptor sites. J Biol Chem 278:20162-70
Moron, Jose A; Zakharova, Irina; Ferrer, Jasmine V et al. (2003) Mitogen-activated protein kinase regulates dopamine transporter surface expression and dopamine transport capacity. J Neurosci 23:8480-8
Uhl, George R (2003) Dopamine transporter: basic science and human variation of a key molecule for dopaminergic function, locomotion, and parkinsonism. Mov Disord 18 Suppl 7:S71-80
Uhl, George R; Lin, Zhicheng (2003) The top 20 dopamine transporter mutants: structure-function relationships and cocaine actions. Eur J Pharmacol 479:71-82
Lin, Zhicheng; Uhl, George R (2003) Human dopamine transporter gene variation: effects of protein coding variants V55A and V382A on expression and uptake activities. Pharmacogenomics J 3:159-68
Liu, Qing-Rong; Zhang, Ping-Wu; Zhen, Qiaoxi et al. (2002) KEPI, a PKC-dependent protein phosphatase 1 inhibitor regulated by morphine. J Biol Chem 277:13312-20