Recombinant Ashbya gossypii Formation of crista junctions protein 1 (FCJ1)
Description
Functional Role of FCJ1 in Mitochondrial Organization
FCJ1 (also known as MIC60 or Mitofilin) is enriched in cristae junctions, specialized structures that connect inner mitochondrial membranes. Key findings from yeast studies include:
This antagonistic interaction between FCJ1 and F1F0-ATP synthase subunits modulates membrane bending, enabling CJ formation and cristae tip organization .
Gene and Protein Information
| Parameter | Value | Source |
|---|---|---|
| Gene Name | MIC60, AFR106C | |
| UniProt ID | Q754G4 | |
| Molecular Weight | ~55 kDa (predicted) | |
| Tag | N-terminal His tag |
Applications and Research Implications
While direct applications of recombinant FCJ1 are not explicitly documented, its study informs:
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Mitochondrial Dynamics: Understanding CJ formation aids in modeling mitochondrial diseases linked to structural defects .
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Biotechnology: Insights into membrane protein folding could optimize heterologous protein secretion in A. gossypii .
Table 1: FCJ1 Amino Acid Sequence Highlights
| Region | Sequence Excerpt | Function |
|---|---|---|
| N-terminal (1–50) | ASTLPPVPRKKSHGVRRLLAKAVVATSLFYAGGLTLSAYNDKANELFVEHVPFGEELVER WEDWTSLRRPGRRMIDARRVDEISRDFRAAATPEATPVVVRPLVQLQLPELQMQGSSPVL EALVNNVNDVVVALNARALELPEDTASALSSVYGEIVHSIQALNASLDQEFATEVESRTG KAISSVQEQLEVEYKQRELALAEQYIQNFEVFKSQLQKATAEQLETELKAHEQALLARHR NEVAQLSIRQVEEFNKIIEKKLDQERNGRLAKLSELNSAVESLAPVLDRLELRAVKNECV TQLSTLISDIQGKLSRGGDEPLDLSSDLQRLTLLADILPRPKRCCSEGPALLDVAMAELQ AKAQAPVASNEQLYNRWQLLQPELKTTSLLPPNAGFLGHLTAKLFSMLLFTKEGFSTTQD MDAVTARIAENLRLNKLDCALEEAVNMKGWSRKSADAWVDLARRRLEVLTLLDVIEAEVK TL | Membrane integration and CJ formation |
Table 2: Recombinant FCJ1 vs. Native FCJ1
| Parameter | Recombinant FCJ1 | Native FCJ1 |
|---|---|---|
| Source | E. coli | A. gossypii mitochondria |
| Post-Translational Modifications | Limited (bacterial system) | Native modifications preserved |
| Purity | >90% | Endogenous expression |
Product Specs
Note: While we prioritize shipping the format currently in stock, please specify your preferred format in order notes for customized fulfillment.
Note: All proteins are shipped with standard blue ice packs. Dry ice shipping requires advance notice and incurs additional charges.
The tag type is determined during production. If you require a specific tag, please inform us, and we will prioritize its development.
Target Background
Recombinant Ashbya gossypii Formation of Crista Junctions protein 1 (FCJ1) is a component of the Mitochondrial Contact Site and Cristae Organization (MICOS) complex. This large protein complex, located in the mitochondrial inner membrane, plays essential roles in maintaining crista junctions, preserving inner membrane architecture, and forming contact sites with the outer membrane. FCJ1 is involved in connecting cristae membranes to the inner boundary membrane and facilitates protein import via the mitochondrial intermembrane space assembly (MIA) pathway.
KEGG: ago:AGOS_AFR106C
STRING: 33169.AAS53477
Q&A
Basic Research Questions
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What is FCJ1 and what is its primary function in mitochondria?
FCJ1 (Formation of Crista Junctions protein 1, also known as MIC60 or Mitofilin) is a conserved mitochondrial inner membrane protein that plays a critical role in maintaining cristae junction structure and organization. It is enriched at cristae junctions (CJs), specialized structures that connect the inner boundary membrane with cristae membranes.
The protein has several key functions:
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Formation and maintenance of cristae junctions
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Organization of the mitochondrial inner membrane architecture
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Antagonistic interaction with F1F0-ATP synthase subunits to regulate membrane curvature
Deletion studies in yeast demonstrate that FCJ1 knockout results in complete loss of cristae junctions and formation of abnormal concentric inner membrane stacks, highlighting its essential structural role.
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How conserved is FCJ1 across different species?
FCJ1 is highly conserved across eukaryotic organisms, particularly within fungal species. Multiple alignment studies reveal significant sequence similarity among homologs from various organisms including:
| Species | Gene/Protein Identifier | Alternative Names |
|---|---|---|
| Ashbya gossypii | AGOS_AFR106C | FCJ1, Mitofilin |
| Saccharomyces cerevisiae | FCJ1 | MIC60, AIM28, FMP13 |
| Candida glabrata | CAGL0G07711g | FCJ1, Mitofilin |
| Debaryomyces hansenii | DEHA2B01716g | FCJ1, Mitofilin |
| Neurospora crassa | Not specified in data | FCJ1 |
| Humans | IMMT | Mitofilin, HMP, P87/89, MINOS2 |
This conservation extends to functional domains, with the C-terminal domain being particularly conserved and critical for function . The high degree of conservation suggests FCJ1's fundamental importance in mitochondrial structure across evolutionary lineages.
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What is the relationship between FCJ1 and the MINOS complex?
FCJ1 is a core component of the MINOS complex (Mitochondrial Inner Membrane Organizing System), a large protein assembly (>1 MDa) essential for cristae organization. Key aspects of this relationship include:
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FCJ1/Mitofilin serves as a scaffolding protein within the MINOS complex
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In yeast, Mio10 (another MINOS component) directly interacts with FCJ1 to maintain inner membrane organization
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The MINOS complex includes additional components such as MINOS1/Mio10, MINOS3/CHCHD3, and others identified through proteomic analyses
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FCJ1-containing MINOS complexes appear in two distinct forms: a low-molecular weight complex and a large protein complex exceeding 1.2 MDa
Importantly, components of the MINOS complex interact with outer membrane proteins, suggesting the complex's role in contact site formation between inner and outer mitochondrial membranes . These interactions position the MINOS complex as a critical mediator of mitochondrial membrane architecture.
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What phenotypes are observed when FCJ1 is deleted or mutated?
FCJ1 deletion or mutation leads to distinctive phenotypes affecting both mitochondrial structure and cellular function:
| Parameter | Observation in FCJ1-deficient cells | Method of Detection |
|---|---|---|
| Growth | Severe growth defects on non-fermentable carbon sources (glycerol), particularly at low temperatures | Serial dilution growth tests |
| Mitochondrial network | Fragmented, enlarged and flattened mitochondria with loss of normal reticular structure | Fluorescence microscopy with mitoGFP |
| Inner membrane architecture | Loss of cristae junctions, formation of concentric inner membrane "onion-like" stacks | Electron microscopy after high-pressure freezing or KMnO₄ fixation |
| F1F0-ATP synthase oligomers | Increased amount of F1F0-ATP synthase oligomers | Blue-native PAGE |
The similarity of phenotypes between fcj1Δ and mio10Δ mutants (another MINOS complex component) further confirms their functional relationship in maintaining mitochondrial cristae morphology .
