Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
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Compound
Target Concepts:
Gene/Protein
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Query: UNIPROT:P10415 (
Bcl-2
)
33,771
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Members of the
Bcl-2
family of proteins play important roles in the regulation of cell death by apoptosis. The yeast Two-Hybrid system was utilized to identify a protein that interacts with the anti-apoptotic protein
Bcl-2
, designated
BMRP
. This protein corresponds to a previously known mitochondrial ribosomal protein (
MRPL41
). Binding experiments confirmed the interaction of
BMRP
to
Bcl-2
in mammalian cells. Subcellular fractionation by differential centrifugation studies showed that both
Bcl-2
and
BMRP
are localized to the same fractions (fractions that are rich in mitochondria). Northern blot analysis revealed a major bmrp mRNA band of approximately 0.8 kb in several human tissues. Additionally, a larger 2.2 kb mRNA species was also observed in some tissues. Western blot analysis showed that endogenous
BMRP
runs as a band of 16-17 kDa in SDS-PAGE. Overexpression of
BMRP
induced cell death in primary embryonic fibroblasts and NIH/3T3 cells. Transfection of
BMRP
showed similar effects to those observed by overexpression of the pro-apoptotic proteins Bax or Bad.
BMRP
-stimulated cell death was counteracted by co-expression of
Bcl-2
. The baculoviral caspase inhibitor p35 also protected cells from
BMRP
-induced cell death. These findings suggest that
BMRP
is a mitochondrial ribosomal protein involved in the regulation of cell death by apoptosis, probably affecting pathways mediated by
Bcl-2
and caspases.
...
PMID:BMRP is a Bcl-2 binding protein that induces apoptosis. 1554 50
Bcl-2
is an anti-apoptotic member of the
Bcl-2
family of proteins that protects cells from apoptosis induced by a large variety of stimuli. The protein
BMRP
(
MRPL41
) was identified as a
Bcl-2
binding partner and shown to have pro-apoptotic activity. We have performed deletion mutational analyses to identify the domain(s) of
Bcl-2
and
BMRP
that are involved in the
Bcl-2
/
BMRP
interaction, and the region(s) of
BMRP
that mediate its pro-apoptotic activity. The results of these studies indicate that both the BH4 domain of
Bcl-2
and its central region encompassing its BH1, BH2, and BH3 domains are required for its interaction with
BMRP
. The loop region and the transmembrane domain of
Bcl-2
were found to be dispensable for this interaction. The
Bcl-2
deletion mutants that do not interact with
BMRP
were previously shown to be functionally inactive. Deletion analyses of the
BMRP
protein delimited the region of
BMRP
needed for its interaction with
Bcl-2
to the amino-terminal two-thirds of the protein (amino acid residues 1-92). Further deletions at either end of the
BMRP
(1-92) truncated protein resulted in lack of binding to
Bcl-2
. Functional studies performed with
BMRP
deletion mutants suggest that the cell death-inducing domains of the protein reside mainly within its amino-terminal two-thirds. The region of
BMRP
required for the interaction with
Bcl-2
is very relevant for the cell death-inducing activity of the protein, suggesting that one possible mechanism by which
BMRP
induces cell death is by binding to and blocking the anti-apoptotic activity of
Bcl-2
.
...
PMID:Deletion mutational analysis of BMRP, a pro-apoptotic protein that binds to Bcl-2. 2125 51
Bcl-2
is an anti-apoptotic protein that inhibits apoptosis elicited by multiple stimuli in a large variety of cell types.
BMRP
(also known as
MRPL41
) was identified as a
Bcl-2
binding protein and shown to promote apoptosis. Previous studies indicated that the amino-terminal two-thirds of
BMRP
contain the domain(s) required for its interaction with
Bcl-2
, and that this region of the protein is responsible for the majority of the apoptosis-inducing activity of
BMRP
. We have performed site-directed mutagenesis analyses to further characterize the
BMRP
/
Bcl-2
interaction and the pro-apoptotic activity of
BMRP
. The results obtained indicate that the 13-17 amino acid region of
BMRP
is necessary for its binding to
Bcl-2
. Further mutagenesis of this motif shows that amino acid residue aspartic acid (D) 16 of
BMRP
is essential for the
BMRP
/
Bcl-2
interaction. Functional analyses conducted in mammalian cells with
BMRP
site-directed mutants
BMRP
(13Ala17) and
BMRP
(D16A) indicate that these mutants induce apoptosis through a caspase-mediated pathway, and that they kill cells slightly more potently than wild-type
BMRP
.
Bcl-2
is still able to counteract
BMRP
(D16A)-induced cell death significantly, but not as completely as when tested against wild-type
BMRP
. These results suggest that the apoptosis-inducing ability of wild-type
BMRP
is blocked by
Bcl-2
through several mechanisms.
...
PMID:Identification of a motif in BMRP required for interaction with Bcl-2 by site-directed mutagenesis studies. 2271 3