Recombinant Chicken 3-hydroxyacyl-CoA dehydratase (PTPLAD1)

What is PTPLAD1 and what are its known synonyms in scientific literature?

PTPLAD1 (Protein-tyrosine phosphatase-like A domain-containing protein 1) is also known by several synonyms including HACD3, RCJMB04_3b6, 3R-3-hydroxyacyl-CoA dehydratase, and 3-hydroxyacyl-CoA dehydratase. This protein is involved in very-long-chain fatty acid (VLCFA) synthesis as part of the elongation cycle in lipid metabolism . The gene encoding this protein is referenced in databases under the name HACD3, with UniProt ID Q5ZM57 for the chicken variant .

How should researchers store and reconstitute recombinant PTPLAD1 protein?

For optimal storage and reconstitution of recombinant PTPLAD1:

• Store the lyophilized protein at -20°C to -80°C upon receipt

• Aliquot to prevent repeated freeze-thaw cycles, which can compromise protein integrity

• For reconstitution:

  • Briefly centrifuge the vial before opening

  • Reconstitute in deionized sterile water to a concentration of 0.1-1.0 mg/mL

  • Add glycerol to a final concentration of 5-50% (50% is standard) for long-term storage

• Short-term working aliquots can be stored at 4°C for up to one week

The protein is typically supplied in a Tris/PBS-based buffer containing 6% Trehalose at pH 8.0, which helps maintain stability during lyophilization and storage .

How does PTPLAD1 affect cellular signaling pathways?

PTPLAD1 has been shown to modulate the Raf/ERK signaling pathway through a specific molecular mechanism. Research indicates that:

• PTPLAD1 binds with prohibitin (PHB) via its middle fragment (amino acids 141-178)

• This binding induces dephosphorylation of PHB at tyrosine-259 (PHB-Y259)

• The dephosphorylation disrupts the interaction between PHB and Raf

• This disruption results in inactivation of Raf/ERK signaling

This mechanism explains how PTPLAD1 can suppress metastasis in colorectal cancer by inhibiting both EMT and mitochondrial fission processes that are critical for cancer progression .

What is the relationship between PTPLAD1 and disease pathology?

PTPLAD1 expression has been negatively associated with poor survival in colorectal cancer patients. Studies show that PTPLAD1 is down-regulated in highly metastatic colorectal cancer cells, and systematic analysis reveals that both EMT and MFT are critical features in colorectal cancer patients with low PTPLAD1 expression. Additionally, PTPLAD1 has been implicated in other diseases including HCV infection and type 2 diabetes .

How can researchers express and purify recombinant chicken PTPLAD1?

Recombinant chicken PTPLAD1 can be expressed and purified using the following general protocol:

• Expression System: Use E. coli as the host organism for protein expression

• Vector Design:

  • Clone the full-length chicken PTPLAD1 sequence (1-362 aa) into an appropriate expression vector

  • Include an N-terminal His-tag for affinity purification

• Expression Conditions:

  • Induce protein expression at optimal temperature and IPTG concentration

  • Harvest cells and lyse using appropriate buffer systems

• Purification:

  • Use Ni-NTA or other His-tag affinity chromatography

  • Consider additional purification steps such as ion exchange or gel filtration

• Quality Control:

  • Analyze purity using SDS-PAGE (should be >90%)

  • Confirm identity using Western blot or mass spectrometry

What methods can be used to study PTPLAD1 interactions with binding partners?

Several methodological approaches can be employed to study PTPLAD1 interactions with binding partners such as PHB:

• Co-immunoprecipitation (Co-IP):

  • Use anti-PTPLAD1 antibodies to pull down protein complexes

  • Identify binding partners through Western blotting or mass spectrometry

• Protein Fragment Analysis:

  • Generate truncated versions of PTPLAD1 to identify specific binding domains

  • The middle fragment (141-178 aa) has been identified as critical for PHB binding

• Phosphorylation Analysis:

  • Use phospho-specific antibodies to detect changes in phosphorylation status of binding partners

  • For example, monitor PHB-Y259 phosphorylation levels in the presence/absence of PTPLAD1

• Fluorescence Resonance Energy Transfer (FRET):

  • Tag PTPLAD1 and suspected binding partners with appropriate fluorophores

  • Analyze protein-protein proximity in living cells

How should researchers design experiments to investigate PTPLAD1's role in cancer models?

When designing experiments to investigate PTPLAD1's role in cancer:

• Expression Modulation:

  • Create stable cell lines with PTPLAD1 overexpression or knockdown

  • Use inducible systems for temporal control of expression

• In Vitro Assays:

  • Cell migration and invasion assays to assess metastatic potential

  • Western blot analysis of EMT markers (E-cadherin, vimentin, Snail)

  • Mitochondrial morphology assessment using fluorescence microscopy

• Signaling Pathway Analysis:

  • Monitor Raf/ERK pathway activation using phospho-specific antibodies

  • Use pathway inhibitors (e.g., U0126 for MEK/ERK) as controls

• In Vivo Models:

  • Inject cancer cells with modified PTPLAD1 expression into immunodeficient mice

  • For example, use a model with 1×10^6 luciferase-expressing cells injected intravenously

  • Monitor metastasis formation through bioluminescence imaging

  • Consider combining with pathway inhibitors or doxycycline-inducible systems

How do post-translational modifications affect PTPLAD1 function?

While specific post-translational modifications of chicken PTPLAD1 are not extensively characterized in the provided search results, this represents an important research direction. Based on its role in signaling and protein-protein interactions, researchers should consider investigating:

• Phosphorylation sites:

  • Identify potential phosphorylation sites using bioinformatics tools

  • Determine if phosphorylation affects binding to partners like PHB

  • Use phospho-mimetic mutations (e.g., Ser/Thr to Asp) to study functional effects

• Other modifications:

  • Investigate potential ubiquitination sites that might regulate protein stability

  • Study acetylation or methylation that could affect protein-protein interactions

• Methodological approaches:

  • Mass spectrometry to identify modification sites

  • Site-directed mutagenesis to create modification-resistant variants

  • Immunoprecipitation with modification-specific antibodies

How can researchers reconcile contradictory findings about PTPLAD1 function in different cellular contexts?

When faced with contradictory findings regarding PTPLAD1 function:

• Context-dependent analysis:

  • Compare experimental conditions, cell types, and tissues used in different studies

  • Determine if PTPLAD1 has tissue-specific binding partners or functions

• Isoform analysis:

  • Verify which PTPLAD1 isoforms were studied in different reports

  • Determine if results differ based on specific protein domains present/absent

• Methodological approaches:

  • Conduct parallel experiments in multiple cell lines to confirm cell-type specificity

  • Use both gain-of-function and loss-of-function approaches in the same system

  • Employ multiple techniques to verify protein-protein interactions (e.g., Co-IP, proximity ligation assay)

• Integrate with broader pathways:

  • Consider PTPLAD1's dual roles in metabolism and signaling

  • Investigate if metabolic conditions affect its signaling functions and vice versa

What are the comparative differences between PTPLAD1 and related proteins like HADH in research applications?

PTPLAD1/HACD3 and HADH (short-chain L-3-hydroxyacyl-CoA dehydrogenase) are both involved in fatty acid metabolism but have distinct properties and research applications:

When choosing between these proteins for research:

• Select PTPLAD1 for studies on fatty acid elongation and EMT signaling

• Choose HADH for investigations of mitochondrial fatty acid oxidation

• Consider both proteins when examining metabolic reprogramming in cancer

What are the critical considerations when designing domain-specific functional studies of PTPLAD1?

When designing domain-specific functional studies:

What are the emerging trends in PTPLAD1 research?

Emerging research on PTPLAD1 reveals its multifunctional nature beyond its canonical role in fatty acid metabolism. Key trends include:

• Dual functionality: Recognition of PTPLAD1 as both a metabolic enzyme and a signaling molecule

• Cancer biology: Increasing evidence for its role as an anti-metastatic factor

• Therapeutic potential: Possible development of strategies to modulate PTPLAD1 activity in cancer treatment

• Structural biology: Efforts to better understand the protein's functional domains

Future research is likely to focus on developing small molecules that can enhance PTPLAD1 activity or mimic its effects on the PHB-Raf interaction, potentially leading to novel cancer therapeutics .

What methodological advances might improve PTPLAD1 research?

Several methodological advances could enhance PTPLAD1 research:

• CRISPR-Cas9 genome editing:

  • Creation of precise domain mutations in endogenous PTPLAD1

  • Generation of conditional knockout models to study tissue-specific functions

• Cryo-EM or X-ray crystallography:

  • Determination of the complete protein structure, especially in complex with binding partners

  • Identification of critical binding pockets for drug design

• Single-cell analysis:

  • Investigation of cell-to-cell variation in PTPLAD1 expression and function

  • Correlation with cellular phenotypes in heterogeneous tumor samples

• Organoid models:

  • Study of PTPLAD1 function in more physiologically relevant 3D culture systems

  • Testing of potential therapeutics in patient-derived organoids

These methodological advances would provide deeper insights into PTPLAD1 biology and accelerate its potential applications in disease treatment .