Recombinant Danio rerio Transmembrane protein 205 (tmem205)

What is Transmembrane protein 205 (TMEM205) in Danio rerio?

TMEM205 in Danio rerio (zebrafish) is a transmembrane protein encoded by the tmem205 gene (also known by the ORF name zgc:158860). It is characterized as a multi-pass membrane protein with predicted transmembrane helices. The protein consists of 188 amino acids and is considered to have four transmembrane domains according to structural annotations . The function of TMEM205 in zebrafish has not been extensively characterized, but related research in human cells suggests potential roles in cisplatin resistance mechanisms, which may indicate conserved functions across species .

What is the amino acid sequence and structural features of zebrafish TMEM205?

The full amino acid sequence of Danio rerio TMEM205 is:
MATEGDPTDFVKVLHLLVISFTWGMQVWVSFIAGFVLISQVSMHTFGLVQSKLFPVYFYCLLLGGNAVSLAV
YAVYHPRELLDWHEGIQLSLFFVAVIMAGLNAQWFGPSATENMLLVMQEIEKEHGLGNQVGMSSNREGYTK
LREQDPKYKEHRSTFYRYHGLSNLCNLIGFFCITVNLIYLALNLGTI

The protein is predicted to contain four transmembrane helices (TMHs) according to UniProt annotations . These hydrophobic regions facilitate its integration into cellular membranes, with both N-terminal and C-terminal regions likely positioned intracellularly based on comparative analysis with homologous proteins.

How conserved is TMEM205 across species compared to the zebrafish variant?

While the search results don't provide direct comparative data on sequence conservation, they indicate functional similarities between zebrafish and human TMEM205. The human ortholog has been implicated in cisplatin resistance mechanisms, suggesting some conserved functional roles . A comprehensive sequence alignment and phylogenetic analysis would be necessary to determine the exact degree of conservation, particularly in the transmembrane domains which are typically more conserved than loop regions in membrane proteins.

What are the optimal storage conditions for recombinant Danio rerio TMEM205?

Recombinant TMEM205 should be stored at -20°C for regular use. For extended storage periods, maintaining the protein at -20°C or -80°C is recommended to preserve structural integrity and functionality . The commercially available recombinant protein is typically provided in a stabilizing buffer containing glycerol (approximately 50%) and a Tris-based buffer optimized for this specific protein . To minimize protein degradation, repeated freeze-thaw cycles should be avoided. For routine experimental work spanning approximately one week, working aliquots can be stored at 4°C .

What expression systems are commonly used for producing recombinant TMEM205?

Recombinant Danio rerio TMEM205 can be expressed in multiple heterologous systems including E. coli, yeast, baculovirus, and mammalian cells . The choice of expression system depends on experimental requirements:

• E. coli systems offer high yield and cost-effectiveness but may not provide proper post-translational modifications

• Yeast systems provide eukaryotic processing capabilities with moderate yield

• Baculovirus expression systems are excellent for producing properly folded transmembrane proteins

• Mammalian cell expression systems ensure the most physiologically relevant post-translational modifications and protein folding

The specific expression system should be selected based on downstream applications and required protein authenticity .

How can researchers verify the purity and activity of recombinant TMEM205?

Commercial recombinant TMEM205 preparations typically exceed 90% purity as verified by electrophoretic methods . Researchers should independently verify purity through:

• SDS-PAGE analysis followed by Coomassie blue staining or silver staining

• Western blotting using specific antibodies against TMEM205 or tag epitopes

• Size exclusion chromatography to assess protein homogeneity

Functional activity assessment is challenging due to limited knowledge of TMEM205's precise function in zebrafish. Based on human TMEM205 research, potential functional assays could include:

• Cisplatin accumulation assays in transfected cells

• Membrane localization studies using confocal microscopy

• Protein-protein interaction assays to identify binding partners

How does TMEM205 expression in zebrafish compare to its expression in human cisplatin-resistant cancer cells?

Human studies have demonstrated that TMEM205 expression is significantly elevated in cisplatin-resistant cancer cell lines compared to cisplatin-sensitive parental lines . While direct comparative expression data between zebrafish and human cells is not provided in the search results, this finding suggests important research directions for zebrafish TMEM205:

• Investigating whether zebrafish TMEM205 expression changes in response to cisplatin exposure

• Determining tissue-specific expression patterns in zebrafish compared to human tissues (where higher expression has been observed in liver, pancreas, and adrenal glands)

• Exploring whether zebrafish models can recapitulate cisplatin resistance mechanisms related to TMEM205 overexpression

Establishing these parallels could validate zebrafish as a model organism for studying cisplatin resistance mechanisms.

What is the potential role of TMEM205 in zebrafish drug resistance mechanisms?

Based on human studies, TMEM205 may play a crucial role in cisplatin resistance through mechanisms affecting drug accumulation. Research with human cells has demonstrated that:

• Stable transfection with TMEM205 confers approximately 2.5-fold resistance to cisplatin

• TMEM205 overexpression is associated with reduced intracellular accumulation of cisplatin

• The protein localizes to the cell surface, suggesting potential involvement in drug efflux or reduced uptake

These findings suggest that zebrafish TMEM205 may similarly modulate drug transport or accumulation. Researchers could investigate whether artificially modulating TMEM205 expression in zebrafish cells affects their sensitivity to cisplatin and other chemotherapeutic agents.

What experimental approaches can be used to study TMEM205 function in zebrafish models?

To investigate TMEM205 function in zebrafish, researchers could employ:

• CRISPR/Cas9 gene editing to create tmem205 knockout or knockdown models

• Transgenic overexpression of TMEM205 using tissue-specific promoters

• Morpholino-based transient knockdown approaches

• Drug sensitivity assays in zebrafish embryos with modified TMEM205 expression

• Fluorescently tagged TMEM205 to track subcellular localization in live zebrafish cells

• RNA-Seq analysis to identify gene expression changes associated with TMEM205 modification

These approaches could help elucidate whether TMEM205 functions in zebrafish similarly to human cells, particularly regarding cisplatin resistance mechanisms.

How can zebrafish TMEM205 research inform human cancer therapy approaches?

Zebrafish TMEM205 research could provide valuable insights for human cancer therapy in several ways:

• Serving as a model system to screen compounds that modulate TMEM205 function

• Identifying regulatory mechanisms controlling TMEM205 expression that might be conserved in humans

• Providing an in vivo platform to test combination therapies targeting TMEM205-mediated drug resistance

• Helping to elucidate the fundamental mechanisms by which TMEM205 contributes to cisplatin resistance

Human studies have already suggested that TMEM205 overexpression may be valuable as a biomarker or therapeutic target in cancer chemotherapy . Zebrafish models could accelerate the development of approaches targeting this mechanism.

What techniques are recommended for studying protein-protein interactions involving TMEM205?

To investigate protein interactions involving zebrafish TMEM205, researchers could employ:

• Co-immunoprecipitation followed by mass spectrometry to identify binding partners

• Yeast two-hybrid screening, with modifications for membrane proteins such as split-ubiquitin systems

• Proximity labeling approaches (BioID or APEX) to identify proteins in close proximity to TMEM205

• Förster resonance energy transfer (FRET) or bimolecular fluorescence complementation (BiFC) to confirm direct interactions in living cells

• Crosslinking mass spectrometry to capture transient interactions

These approaches need to account for the challenges of studying membrane proteins, including proper solubilization and maintaining native conformations during experimental procedures.

What are common challenges in expressing and purifying recombinant TMEM205?

Transmembrane proteins like TMEM205 present several challenges during recombinant expression and purification:

• Protein misfolding or aggregation due to hydrophobic transmembrane domains

• Cytotoxicity when overexpressed in host cells

• Low yield compared to soluble proteins

• Difficulties in extracting the protein from membranes while maintaining native conformation

• Requirement for detergents or lipid environments to maintain stability during purification

To address these challenges, researchers should consider:

• Using specialized expression hosts designed for membrane proteins

• Optimizing growth conditions (temperature, induction time)

• Testing different detergents or nanodiscs for protein extraction and stabilization

• Employing fusion partners that enhance solubility

• Using affinity tags positioned to minimize interference with protein folding

How can researchers validate antibody specificity for Danio rerio TMEM205?

Validating antibody specificity for zebrafish TMEM205 requires multiple approaches:

• Western blot analysis comparing wild-type samples with TMEM205 knockout or knockdown samples

• Immunoprecipitation followed by mass spectrometry to confirm target identity

• Peptide competition assays, where the antibody is pre-incubated with the immunizing peptide

• Testing antibody reactivity across tissues with known differential expression patterns

• Immunofluorescence microscopy to confirm expected subcellular localization patterns

• Cross-validation using multiple antibodies targeting different epitopes of TMEM205

These validation steps are essential because non-specific antibody binding can lead to misinterpretation of experimental results, particularly for less-studied proteins like zebrafish TMEM205.

What controls should be included in functional studies of TMEM205 in zebrafish?

Robust functional studies of zebrafish TMEM205 should include:

• Positive controls: Cells or organisms with confirmed TMEM205 overexpression

• Negative controls: TMEM205 knockout or knockdown models

• Specificity controls: Rescue experiments reintroducing TMEM205 in knockout models

• Technical controls: Multiple targeting strategies (different siRNAs, CRISPR guides) to rule out off-target effects

• Phenotypic controls: Analysis of related transmembrane proteins to demonstrate specificity of TMEM205-associated phenotypes

• Dose-response controls: When studying drug resistance, establishing proper dose-response curves for both wild-type and TMEM205-modified models

For cisplatin resistance studies specifically, detailed accumulation assays using fluorescently labeled cisplatin compounds (such as Alexa Fluor-cisplatin) would help verify whether zebrafish TMEM205 affects drug accumulation similarly to human TMEM205 .