PMID- 10066734
OWN - NLM
STAT- MEDLINE
DCOM- 19990413
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 274
IP  - 11
DP  - 1999 Mar 12
TI  - Targeted construction of phosphorylation-independent beta-arrestin mutants with
      constitutive activity in cells.
PG  - 6831-4
AB  - Arrestin proteins play a key role in the desensitization of G protein-coupled
      receptors (GPCRs). Recently we proposed a molecular mechanism whereby arrestin
      preferentially binds to the activated and phosphorylated form of its cognate
      GPCR. To test the model, we introduced two different types of mutations into
      beta-arrestin that were expected to disrupt two crucial elements that make
      beta-arrestin binding to receptors phosphorylation-dependent. We found that two
      beta-arrestin mutants (Arg169 --> Glu and Asp383 --> Ter) (Ter, stop codon) are
      indeed "constitutively active." In vitro these mutants bind to the
      agonist-activated beta2-adrenergic receptor (beta2AR) regardless of its
      phosphorylation status. When expressed in Xenopus oocytes these beta-arrestin
      mutants effectively desensitize beta2AR in a phosphorylation-independent manner. 
      Constitutively active beta-arrestin mutants also effectively desensitize delta
      opioid receptor (DOR) and restore the agonist-induced desensitization of a
      truncated DOR lacking the critical G protein-coupled receptor kinase (GRK)
      phosphorylation sites. The kinetics of the desensitization induced by
      phosphorylation-independent mutants in the absence of receptor phosphorylation
      appears identical to that induced by wild type beta-arrestin + GRK3. Either of
      the mutations could have occurred naturally and made receptor kinases redundant, 
      raising the question of why a more complex two-step mechanism (receptor
      phosphorylation followed by arrestin binding) is universally used.
FAU - Kovoor, A
AU  - Kovoor A
AD  - Department of Pharmacology, University of Washington, Seattle, Washington
      98195-7280, USA.
FAU - Celver, J
AU  - Celver J
FAU - Abdryashitov, R I
AU  - Abdryashitov RI
FAU - Chavkin, C
AU  - Chavkin C
FAU - Gurevich, V V
AU  - Gurevich VV
LA  - eng
GR  - R37 DA011672/DA/NIDA NIH HHS/United States
GR  - DA 04123/DA/NIDA NIH HHS/United States
GR  - EY 11500/EY/NEI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Arrestins)
RN  - 0 (Receptors, Adrenergic, beta)
RN  - 0 (beta-Arrestins)
RN  - EC 3.6.1.- (GTP-Binding Proteins)
SB  - IM
MH  - Animals
MH  - Arrestins/genetics/*metabolism
MH  - GTP-Binding Proteins/metabolism
MH  - Mutagenesis, Site-Directed
MH  - Phosphorylation
MH  - Receptors, Adrenergic, beta/metabolism
MH  - Xenopus
MH  - beta-Arrestins
EDAT- 1999/03/06 00:00
MHDA- 1999/03/06 00:01
CRDT- 1999/03/06 00:00
PHST- 1999/03/06 00:00 [pubmed]
PHST- 1999/03/06 00:01 [medline]
PHST- 1999/03/06 00:00 [entrez]
AID - 10.1074/jbc.274.11.6831 [doi]
AID - S0021-9258(18)36945-X [pii]
PST - ppublish
SO  - J Biol Chem. 1999 Mar 12;274(11):6831-4. doi: 10.1074/jbc.274.11.6831.