RVS167 Antibody

What is RVS167 and what cellular functions does it mediate?

RVS167 is a BAR domain-containing protein that plays essential roles in membrane reshaping during cellular processes. In yeast models, RVS167 functions in regulation of the actin cytoskeleton, endocytosis, cell polarity maintenance, and vesicle trafficking . The protein forms a heterodimer with RVS161, and this complex specifically localizes to sites of endocytosis marked by actin-binding protein 1 (Abp1) . Notably, while RVS167 strictly colocalizes with endocytic marker Abp1, the paralog RVS167-3 (which forms a heterodimer with RVS162) shows distinct localization patterns, suggesting divergent functions of these BAR protein complexes .

How do RVS167 antibodies function in experimental contexts?

RVS167 antibodies serve as essential tools for detecting and analyzing RVS167 protein in diverse experimental settings. These antibodies bind specifically to RVS167 epitopes and enable visualization and quantification through techniques such as Western blotting, immunoprecipitation, and immunofluorescence microscopy . For effective immunoprecipitation, researchers typically use cells lysed in buffers containing 50 mM Tris-Cl (pH 7.4), 250 mM NaCl, 50 mM NaF, 0.1% NP-40, and appropriate protease inhibitors . After pre-clearing with protein A-Sepharose, lysates are incubated with anti-RVS167 antibodies (or anti-HA for tagged versions) coupled to protein A-Sepharose, followed by washing and elution procedures .

What are critical sample preparation considerations for RVS167 antibody experiments?

Proper sample preparation is crucial for successful RVS167 antibody experiments. Cell lysis conditions must preserve protein integrity while efficiently extracting membrane-associated proteins. For co-immunoprecipitation studies, researchers should note that RVS167 stability depends on its dimerization partner RVS161, and deletion of either gene affects the stability of its partner protein . When preparing samples for Western blotting, protein concentration should be carefully measured using Bradford assays, and equivalent amounts loaded for comparative analyses . For immunofluorescence localization studies, fixation methods should preserve membrane structures where RVS167 typically localizes.

How can researchers differentiate between RVS167-containing complexes?

Distinguishing between different RVS167-containing complexes requires careful experimental design. In Candida albicans, researchers have identified two distinct BAR heterodimers: the canonical RVS161/RVS167 complex involved in endocytosis and the novel RVS162/RVS167-3 complex with different functions . To differentiate these complexes, researchers can employ co-immunoprecipitation with specific antibodies against each protein component followed by Western blotting . Localization studies using fluorescently tagged proteins and co-localization analysis with established markers (such as Abp1 for endocytic sites) provide additional discrimination between these complexes .

What methodological approaches reveal RVS167 membrane association dynamics?

To investigate RVS167 membrane association dynamics, researchers can implement several complementary approaches:

• In vitro liposome binding assays: Purified RVS161/RVS167 heterodimers bind phospholipid membranes in vitro, indicating direct membrane association capabilities . These assays can be performed with varying lipid compositions to assess binding preferences.

• Live-cell imaging with GFP-tagged proteins: RVS167-GFP concentrates in small cortical spots that correspond to sites of endocytosis . Time-lapse microscopy reveals the temporal dynamics of these associations.

• FM4-64 internalization assays: This lipophilic dye can be used to track endocytosis rates in wild-type versus rvs mutant strains, providing functional readouts of membrane dynamics .

• Immunoelectron microscopy: Ultra-structural localization of RVS167 at membrane invaginations can provide detailed spatial information about its association with specific membrane compartments.

How do genetic backgrounds influence interpretation of RVS167 antibody experiments?

Genetic background significantly impacts RVS167 antibody experiment interpretation. The rvs161Δ/Δ and rvs167Δ/Δ mutants display identical phenotypes, including increased sensitivity to high salt conditions, cell wall-disturbing compounds (calcofluor white, Congo red), and oxidative stress agents . Intriguingly, the rvs167-3Δ/Δ strain shows enhanced tolerance to high salt and growth at low temperature compared to wild-type, and deletion of either RVS161 or RVS167 suppresses this phenotype . This genetic interaction between RVS167-3 and the RVS161/RVS167 heterodimer indicates complex functional relationships that must be considered when designing and interpreting experiments . Researchers should include appropriate genetic controls and consider how mutations might affect protein stability and complex formation.

What are optimal conditions for immunoprecipitation with RVS167 antibodies?

For successful immunoprecipitation of RVS167, researchers should implement the following protocol based on published literature:

• Harvest log-phase cells in immunoprecipitation lysis buffer containing:

  • 50 mM Tris-Cl, pH 7.4

  • 250 mM NaCl

  • 50 mM NaF

  • 0.1% NP-40

  • 40 mM β-glycerophosphate

  • 5 mM EDTA

  • 1 mM DTT

  • Protease inhibitors (PMSF, sodium orthovanadate, etc.)

• Lyse cells by vortexing with glass beads and clear lysate by centrifugation

• Pre-clear lysate with protein A-Sepharose (300 μl per 100 mg lysate) for 1 hour

• Incubate with antibody (anti-RVS167 or anti-tag if using tagged versions) coupled to protein A-Sepharose for 1 hour

• Wash beads thoroughly with lysis buffer (3 × 5 ml)

• Elute bound proteins by boiling in SDS sample buffer

For co-immunoprecipitation studies aimed at detecting interaction partners, gentler lysis conditions may better preserve protein-protein interactions.

What controls are essential for validating RVS167 antibody specificity?

To ensure experimental rigor when working with RVS167 antibodies, researchers should incorporate these essential controls:

• Genetic validation controls:

  • Wild-type strain (positive control)

  • rvs167Δ deletion strain (negative control)

  • rvs161Δ strain (to assess effects on RVS167 stability)

• Immunoblotting controls:

  • Non-specific primary antibody of the same isotype

  • Secondary antibody-only control

  • Unrelated protein control (e.g., antibodies against Crn1p have been used)

• Co-immunoprecipitation specificity controls:

  • Reciprocal co-IP (e.g., IP with anti-RVS161 and blot for RVS167)

  • IgG control immunoprecipitation

  • Competitive peptide blocking

These controls help distinguish specific signals from background and validate antibody specificity in different experimental contexts.

How can researchers resolve RVS167 detection issues in mutant strains?

Detection challenges with RVS167 in mutant backgrounds often stem from protein stability issues. Research demonstrates that each RVS gene is required for the stability of its protein partner during vegetative growth . When troubleshooting detection problems:

• For reduced or absent RVS167 signal in rvs161Δ backgrounds:

  • Increase protein loading amounts

  • Use more sensitive detection methods (e.g., enhanced chemiluminescence systems)

  • Consider shorter intervals between sample preparation and analysis to minimize degradation

  • Use proteasome inhibitors to prevent protein degradation

• For RVS167-3 detection issues:

  • Note that RVS167-3 stability depends on RVS162, though interestingly, RVS162 levels are not affected by deletion of RVS167-3

  • In contrast, deletion of RVS161 does not affect actin patch localization of RVS167, suggesting independent localization mechanisms

• For non-specific bands:

  • Optimize antibody concentration and washing conditions

  • Consider using more specific monoclonal antibodies if available

  • Include appropriate blocking agents to reduce background

What approaches help resolve conflicting RVS167 localization data?

When faced with contradictory RVS167 localization results, researchers should systematically address potential methodological variables:

• Fixation method comparison:

  • Different fixation protocols may preserve or disrupt certain protein-membrane interactions

  • Compare chemical fixation (formaldehyde, glutaraldehyde) with quick-freezing methods

  • Validate with live-cell imaging when possible

• Tagging considerations:

  • N- versus C-terminal tags may differentially affect protein localization

  • Compare results with multiple tagging approaches

  • Validate tagged constructs with functional complementation assays

• Resolution limitations:

  • Standard fluorescence microscopy may not resolve closely adjacent structures

  • Consider super-resolution approaches for fine localization patterns

  • Correlative light and electron microscopy can provide multi-scale localization data

• Contextual analysis:

  • Always analyze RVS167 localization in relation to established markers like Abp1

  • Consider cell cycle stage and growth conditions when interpreting localization patterns

  • Quantitative co-localization analysis provides more objective assessment than visual inspection

How can researchers determine if RVS167 BAR domain mutations affect membrane binding?

To assess the impact of BAR domain mutations on RVS167 membrane binding capabilities, researchers can implement a multi-tiered approach:

These complementary approaches provide comprehensive assessment of how specific mutations affect both molecular interactions and cellular functions of RVS167 .

What methodologies reveal RVS167's role in actin dynamics?

The relationship between RVS167 and actin cytoskeleton can be investigated through several sophisticated approaches:

• Actin patch dynamics analysis:

  • Time-lapse imaging of fluorescently tagged actin in wild-type versus rvs167Δ cells

  • Quantification of patch lifetime, movement, and internalization rates

  • Two-color imaging with RVS167-GFP and actin markers to determine temporal relationship

• Biochemical interaction studies:

  • Two-hybrid analysis using RVS167 fragments and actin

  • The SH3 domain of RVS167 has been implicated in actin interaction

  • "Charged-to-alanine" scanning mutagenesis of actin reveals that mutations affecting interaction with RVS167 also affect interaction with profilin

  • Co-immunoprecipitation assays to detect direct or indirect associations

• Domain-specific analysis:

  • The SH3 domain of RVS167 interacts with proline-rich motifs (PXXP)

  • Actin contains a single potential SH3-binding motif (PMNP)

  • Deletion of the SH3 domain abolishes the two-hybrid interaction with actin

  • Current evidence suggests the RVS167-actin interaction may be indirect and potentially mediated by another protein

These methodologies collectively provide a framework for understanding RVS167's contributions to actin cytoskeletal regulation.

How can differential RVS167 complex functions be leveraged in experimental design?

The discovery that C. albicans expresses two distinct BAR heterodimers (RVS161/RVS167 and RVS162/RVS167-3) with different functions creates unique experimental opportunities . Researchers can leverage these differences to:

• Develop selective inhibitors or modulators:

  • Target specific heterodimer interfaces

  • Design compounds that specifically disrupt one complex but not the other

• Create domain-swapping experiments:

  • Exchange domains between RVS167 and RVS167-3 to determine which regions confer functional specificity

  • Analyze how these chimeric proteins localize and function

• Investigate genetic interactions:

  • The rvs167-3Δ/Δ strain shows increased tolerance to high salt concentrations and growth at low temperature

  • This tolerance is suppressed by deletion of either RVS161 or RVS167

  • This genetic interaction framework provides a platform for identifying other factors involved in membrane dynamics

• Develop differential antibodies and biosensors:

  • Create antibodies that specifically recognize each complex

  • Design FRET-based sensors that report on heterodimer formation or membrane association

These approaches exploit the natural diversity of RVS complexes to probe membrane dynamics with unprecedented specificity.

What considerations apply when analyzing RVS167 in non-yeast systems?

When extending RVS167 research beyond yeast models, researchers should consider several methodological adaptations:

• Ortholog identification:

  • BAR domain proteins exist across eukaryotes but may have divergent sequences

  • Multiple sequence alignment and phylogenetic analysis help identify true functional orthologs

• Antibody cross-reactivity assessment:

  • Yeast-derived antibodies may not recognize orthologs in other species

  • Epitope conservation analysis helps predict cross-reactivity

  • Validation in knockout/knockdown systems is essential

• Functional conservation testing:

  • Complementation assays (can the non-yeast ortholog rescue yeast mutant phenotypes?)

  • Conservation of interaction partners across species

  • Similar subcellular localization patterns

• System-specific controls:

  • Include tissue-specific expression analysis

  • Consider developmental regulation not present in unicellular systems

  • Account for potential redundancy with other BAR proteins

The search results indicate that related BAR proteins exist across many species, with genes encoding BAR family members found ubiquitously , suggesting broad evolutionary conservation of these membrane-shaping mechanisms.