ptrn-1 Antibody
Product Specs
Target Background
KEGG: cel:CELE_F35B3.5
STRING: 6239.F35B3.5a
Q&A
Basic Research Questions
What cellular functions does PTRN-1 regulate in C. elegans?
PTRN-1 stabilizes microtubule networks and facilitates actin dynamics during endocytic recycling. Key methodologies to study this include:
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Genetic mutants: Use ptrn-1(tm5597) null mutants to observe defects in actin organization via GFP-Utrophin-CH or Lifeact-GFP markers .
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Rescue experiments: Express PTRN-1 truncations (e.g., PTRN-1∆CKK) to assess functional domains .
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Phalloidin staining: Quantify actin filament density in intestinal epithelia .
How is PTRN-1 localized within cells?
PTRN-1 localizes to microtubule-rich structures and partially overlaps with actin networks. Experimental approaches:
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Fluorescent tagging: Express PTRN-1a-mCherry fusion proteins (ycxEx829) and compare with EMTB-GFP microtubule markers .
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Domain truncation analysis: Test GFP-tagged fragments (e.g., CH domain vs. CC region) to map localization signals .
What model systems are suitable for studying PTRN-1?
C. elegans is the primary model due to tractable genetics and visible phenotypes:
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Axon regeneration assays: Laser axotomy in ptrn-1 mutants reveals impaired regrowth and elevated microtubule dynamics .
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Intestinal epithelia: Monitor endocytic recycling defects using hTAC-GFP reporters .
Advanced Research Questions
How do PTRN-1 domains synergize to regulate cytoskeletal dynamics?
The CH domain interacts with CYK-1/formin to promote actin polymerization, while the CC region stabilizes microtubules. Critical methods:
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Co-sedimentation assays: Test CH domain binding to CYK-1’s GTPase-binding domain (GBD) .
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Domain-specific truncations: Compare rescue efficiency of PTRN-1∆CKK (CH+CC) vs. PTRN-1∆CH (CC+CKK) in recycling assays .
Table 1: Functional domains of PTRN-1
| Domain | Function | Rescue Capability (hTAC-GFP) |
|---|---|---|
| CH (1–359) | Binds CYK-1/formin | Partial |
| CC (360–899) | Stabilizes microtubules | None |
| CKK (899–1,110) | Minus-end microtubule anchoring | None |
| CH+CC (1–899) | Synergistic actin-microtubule crosstalk | Full rescue |
How to resolve contradictions in PTRN-1’s actin-binding activity?
While the CH domain is essential for actin dynamics, in vitro co-sedimentation assays show no direct CH-F-actin binding . Strategies:
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In vivo vs. in vitro testing: Use FRET or TIRF microscopy to observe real-time CH-actin interactions.
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Genetic epistasis: Combine ptrn-1 mutants with cyk-1/formin RNAi to dissect indirect regulatory roles .
What methodologies quantify PTRN-1’s impact on microtubule stability?
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Microtubule regrowth assays: Induce microtubule depolymerization (e.g., cold shock) and track regrowth rates in ptrn-1 mutants .
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DLK-1 MAPK pathway analysis: Measure phosphorylation levels of DLK-1 substrates to assess PTRN-1’s inhibitory role in developing neurons .
Table 2: Phenotypic comparison of ptrn-1 mutants
| Process | Wild-Type Phenotype | ptrn-1 Mutant Phenotype |
|---|---|---|
| Axon regeneration | Robust regrowth | Delayed, disorganized axons |
| Actin density | High | Reduced (~50% by phalloidin) |
| Microtubule dynamics | Stable | Hyperdynamic (2x turnover) |
How to design truncation mutants for domain-function studies?
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CRISPR/Cas9 editing: Generate intragenic deletions (e.g., tm5597 allele) to create nonsense mutations .
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Transgenic rescue: Express domain-specific fragments (e.g., aa 1–359 for CH) under tissue-specific promoters .
Methodological Insights
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Co-sedimentation assays: Use 10 µM F-actin + purified CH domain (aa 1–359) in high-speed centrifugation buffers to detect weak interactions .
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Multi-round evolution: For antibody engineering (e.g., trastuzumab), apply constrained integer linear programming to balance diversity and fitness .
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Language model-guided mutagenesis: Rank single-residue substitutions using ESM-1b/ESM-1v models to prioritize evolutionarily plausible mutations .
