Gene or accession: CG8627
Missed gene
Comments:
Dear FlyBase Curators,
Correct annotation would be: acyl-coa binding protein
\- binds Acyl-CoA
\- acts as a transporter and/or pool-former of Acyl-CoA
Synonyms (aliases) for DBI:
\- diazepam-binding protein (DBI)
\- acyl-CoA binding protein (ACBP)
\- endozepine
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1. Many possible biological roles have been suggested for DBI
\- binding of Acyl-CoA
\- stimulation of steroidogenesis through peripheral benzodiazepine
receptors (also known as mitochondrial benzodiazepine receptors)
\- modulation of GABA receptor type A (DBI/ACBP protein was first
purified and also named on the bases of its ability to inhibit
diazepam binding to GABA receptors of type A)
\- stimulation of insulin secretion
\- antibacterial properties
\- stimulation of cholecystokinin (CCK) secretion
\- binding of lead (lead-binding protein)
2. However the binding of Acyl-CoA is the only function of DBI/ACBP
which has been supported with remarkable body of experimental evidence.
3. Evidence:
\- extensive biochemical data \- for a reviews:
Kragelund BB et al.
Biochim Biophys Acta. 1999 Nov 23;1441(2-3):150-61. Review.
Knudsen J et. al.
Mol Cell Biochem. 1999 Feb;192(1-2):95-103. Review.
\- three-dimensional structure of ACBP/DBI and palmitoyl-CoA has
been resolved by multidimensional nuclear magnetic resonance (NMR)
spectroscopy
Kragelund BB, et al.
J Mol Biol. 1993 Apr 20;230(4):1260-77.
\- knock-out experiments in S. cerevisiae
Schjerling CK et. al.
J Biol Chem. 1996 Sep 13;271(37):22514-21.
\- please note that DBI/ACBP has been conserved throughout the
evolution and is found in unicellular eukaryote S. cerevisiae and
also in prokaryote Deinococcus radiodurans. Therefore it is highly
unlikely that the real function of ACBP/DBI would be binding of
diazepam.....
4. Our own studies have shown that in D. melanogaster the expression of
ACBP/DBI is expressed in the following tissues:
\- outer vacuolate epithelium of the stomodeal valve of the cardia
\- in distal part of the anterior Malpighian tubules,
\- fat body,
\- gametes of both sexes
\- pupal and larval brains (no expression in adult CNS).
Localization and morphological characteristics of structures
that do express DBI/ACBP suggest that these structures are most
likely glial cells and their processes.
Kolmer M, et. al.
Mol Cell Biol. 1994 Oct;14(10):6983-95.
5. On the basis of the expression of DBI in some but not all tissues
with high energy consumption, we proposed that in D. melanogaster,
DBI is involved in energy metabolism in a manner that depends on
the substrate used for energy production (most likely Acyl-CoA,
however we have no direct experimental evidence so far).
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Finally, please also see a Swiss-Prot annotation line below
(entry name: ACBP_BOVIN)
FUNCTION: BINDS MEDIUM- AND LONG-CHAIN ACYL-COA ESTERS WITH VERY
HIGH AFFINITY AND MAY FUNCTION AS AN INTRACELLULAR CARRIER OF
ACYL-COA ESTERS. IT IS ALSO ABLE TO DISPLACE DIAZEPAM FROM THE
BENZODIAZEPINE (BZD) RECOGNITION SITE LOCATED ON THE GABA TYPE A
RECEPTOR. IT IS THEREFORE POSSIBLE THAT THIS PROTEIN ALSO ACTS AS A
NEUROPEPTIDE TO MODULATE THE ACTION OF THE GABA RECEPTOR.
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Thank you for your time and for keeping FlyBase up and running.
with all the best wishes, Meelis