BID Protein

BID Protein

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">BID Protein</th>
</tr>
<tr>
<td class="label">Gene</td>
<td>[BID](/genes/bid)</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/P55957" target="_blank">P55957</a></td>
</tr>
<tr>
<td class="label">PDB</td>
<td><a href="https://www.rcsb.org/structure/1DDB" target="_blank">1DDB</a>, <a href="https://www.rcsb.org/structure/2BID" target="_blank">2BID</a></td>
</tr>
<tr>
<td class="label">Mol. Weight</td>
<td>22 kDa (full-length), 15 kDa (truncated)</td>
</tr>
<tr>
<td class="label">Localization</td>
<td>Cytoplasm, mitochondrial outer membrane</td>
</tr>
<tr>
<td class="label">Family</td>
<td>BCL2 family, BH3-only proteins</td>
</tr>
<tr>
<td class="label">Diseases</td>
<td>[Alzheimer's Disease](/diseases/alzheimers), [Parkinson's Disease](/diseases/parkinsons-disease), [ALS](/diseases/als), [Stroke](/diseases/stroke)</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/ataxia" style="color:#ef9a9a">Ataxia</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">190 edges</a></td>
</tr>
</table>

BID Protein

Introduction

...

BID Protein

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">BID Protein</th>
</tr>
<tr>
<td class="label">Gene</td>
<td>[BID](/genes/bid)</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/P55957" target="_blank">P55957</a></td>
</tr>
<tr>
<td class="label">PDB</td>
<td><a href="https://www.rcsb.org/structure/1DDB" target="_blank">1DDB</a>, <a href="https://www.rcsb.org/structure/2BID" target="_blank">2BID</a></td>
</tr>
<tr>
<td class="label">Mol. Weight</td>
<td>22 kDa (full-length), 15 kDa (truncated)</td>
</tr>
<tr>
<td class="label">Localization</td>
<td>Cytoplasm, mitochondrial outer membrane</td>
</tr>
<tr>
<td class="label">Family</td>
<td>BCL2 family, BH3-only proteins</td>
</tr>
<tr>
<td class="label">Diseases</td>
<td>[Alzheimer's Disease](/diseases/alzheimers), [Parkinson's Disease](/diseases/parkinsons-disease), [ALS](/diseases/als), [Stroke](/diseases/stroke)</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/ataxia" style="color:#ef9a9a">Ataxia</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">190 edges</a></td>
</tr>
</table>

BID Protein

Introduction

Bid Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

BID (BH3-interacting domain death agonist) is a unique pro-apoptotic member of the BCL2 family that links the extrinsic (death receptor) and intrinsic (mitochondrial) pathways of [apoptosis](/entities/apoptosis)[@wang2001]. BID is particularly important in [neurons](/entities/neurons) following various pathological insults including excitotoxicity, oxidative stress, and ischemia[@kantari2007].

The BID gene encodes a 195-amino acid protein that exists in both full-length (inactive) and truncated (active) forms. Proteolytic cleavage by caspases converts BID to its active form (tBID), which then translocates to mitochondria to initiate apoptosis[@merino2009].

Structure

BID has a distinctive structure:

Full-Length BID

• N-terminal regulatory domain
• C-terminal BH3 domain (partially obscured)
• Requires proteolytic activation

Truncated BID (tBID)

• Generated by caspase-8 or caspase-3 cleavage
• Exposes the BH3 domain
• Trimerizes and localizes to mitochondria
• Highly potent at inducing apoptosis

BH3 Domain

The BH3 domain (residues 80-120) mediates:

• Interaction with anti-apoptotic BCL2 proteins
• Direct activation of BAX/BAK
• Membrane targeting[@singh2015]

Normal Function

Apoptosis Pathway Integration

BID serves as a bridge between death receptor and mitochondrial pathways:

Extrinsic Pathway: Death receptor activation → caspase-8 → tBID

Mitochondrial Pathway: tBID → BAX/BAK activation → cytochrome c release

Amplification: Intrinsic pathway can further cleave BID

Non-Apoptotic Functions

BID has roles beyond apoptosis:

• Mitochondrial dynamics regulation
• [Autophagy](/entities/autophagy) modulation
• Cell cycle regulation
• [Necroptosis](/entities/necroptosis) regulation

Tissue-Specific Functions

In neurons, BID:

• Mediates excitotoxic cell death
• Participates in developmental pruning
• Responds to various stress signals[^5]

Role in Disease

Alzheimer's Disease

BID contributes to AD pathogenesis:

• [Amyloid-beta](/proteins/amyloid-beta) triggers BID cleavage
• tBID levels increase in AD brains
• BID-mediated apoptosis contributes to neuronal loss

Parkinson's Disease

In PD:

• Mitochondrial dysfunction activates BID
• 6-OHDA and MPTP activate BID pathway
• BID deletion protects dopaminergic neurons

ALS

In motor neuron disease:

• Mutant SOD1 activates BID
• Excitotoxic insults trigger BID cleavage
• BID contributes to motor neuron apoptosis

Stroke/Ischemia

BID is activated in ischemic brain injury:

• Cerebral ischemia cleaves BID
• tBID mediates infarct formation
• BID deficiency reduces damage[^6]

Therapeutic Targeting

Therapeutic strategies include:

• Caspase inhibitors: Prevent BID activation
• BID BH3 mimetics: Blocking peptides
• Anti-apoptoticBCL2 activators: Sequester active BID
• Neuroprotective compounds: Prevent BID activation downstream

Background

The study of Bid Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

See Also

• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [ALS](/diseases/amyotrophic-lateral-sclerosis)
• BCL2 Family
• [Apoptosis](/mechanisms/apoptosis)

Related Analyses:

• [Is disrupted sleep a cause or consequence of neurodegeneration? Analyze the bidirectional relationsh](/analysis/SDA-2026-04-02-gap-20260402-003058) &#x1f504;
• [Is disrupted sleep a cause or consequence of neurodegeneration? Analyze the bidirectional relationsh](/analysis/SDA-2026-04-02-gap-20260402-003115) &#x1f504;