unc-84 Antibody
Description
Introduction to UNC-84 and Its Antibody
UNC-84 is a nuclear envelope protein that recruits KASH-domain proteins (e.g., UNC-83, ANC-1) to mediate nuclear positioning and maintain nuclear envelope (NE) integrity . The unc-84 antibody is a polyclonal antibody raised against synthetic peptides of UNC-84, enabling its detection in developmental studies and functional analyses .
Antibody Generation and Validation
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Immunization: Antibodies were generated in mice and rats using a synthetic peptide (CAVWKWIGNQSQKRW-COOH) corresponding to residues 1–14 of UNC-84, conjugated to keyhole limpet hemocyanin (KLH) .
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Specificity: Western blotting identified two UNC-84 isoforms (125 kDa and 99 kDa) in wild-type C. elegans, absent in unc-84(n369) null mutants .
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Applications: Used for immunofluorescence, protein blotting, and colocalization studies with nuclear lamins .
Localization and Expression Patterns
UNC-84 localizes to the nuclear envelope in nearly all somatic cells starting from the 26-cell embryonic stage . Key findings include:
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Colocalization: Co-staining with Ce-lamin confirmed UNC-84’s association with the nuclear lamina .
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Developmental Expression: Detected in all somatic cells post-embryogenesis but absent in germline mitotic cells until pachytene stages .
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Subcellular Fractionation: UNC-84 behaves as an integral membrane protein, resisting extraction with 1 M NaCl or 8 M urea .
Nuclear Migration and Anchorage
UNC-84 recruits UNC-83 to the outer nuclear membrane (ONM), forming a bridge across the NE to mediate nuclear migration . Loss of UNC-84 disrupts nuclear positioning in hypodermal cells .
DNA Damage Repair
UNC-84 promotes homologous recombination (HR) by recruiting FAN-1 nuclease and inhibiting nonhomologous end joining (NHEJ). unc-84 mutants exhibit hypersensitivity to DNA cross-linking agents .
Nuclear Envelope Architecture
Despite its role in nuclear migration, UNC-84 is dispensable for maintaining NE spacing in non-force-bearing cells, as shown by TEM studies .
Table 1: UNC-84 Constructs and Nuclear Migration Rescue
| UNC-84 Construct | Line | Nuclei in Dorsal Cord (Mean ± SD) |
|---|---|---|
| Wild-type (N2) | N2 | 0 ± 0 |
| unc-84(n369) null | MT369 | 14.3 ± 1.5 |
| UNC-84 rescuing construct | UD87 | 0.2 ± 0.5 |
| UNC-84ΔSUN | UD61 | 14.8 ± 1.1 |
| Data from McGee et al. (2006) . |
Table 2: Transmembrane Domain Deletion Analysis
| Deleted Region (Residues) | Localization Efficiency |
|---|---|
| ΔH1 (386–406) | Normal NE targeting |
| ΔH2 (512–532) | Mislocalized |
| ΔH3 (685–705) | Partial mislocalization |
| Data from Tapley et al. (2011) . |
Mechanisms of UNC-84 Targeting to the Nuclear Envelope
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N-Terminal Domain: Residues 1–535 are sufficient for NE localization, while the C-terminal SUN domain is dispensable for targeting but essential for function .
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Critical Regions: Deletion of residues 118–244 disrupts NE localization, suggesting this region interacts with nuclear lamins or contains a nuclear import signal .
Role in LINC Complexes and DNA Repair
UNC-84 interacts with ZYG-12 (a KASH protein) to form a functional linker of nucleoskeleton and cytoskeleton (LINC) complex. This interaction is critical for:
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
- SUN-KASH bridges are essential for maintaining nuclear envelope spacing in cells subjected to increased mechanical forces. PMID: 25023515
- Targeting UNC-84 involves an initial step that actively transports UNC-84 from the peripheral endoplasmic reticulum to the nuclear envelope. PMID: 21411627
- UNC-84 and UNC-83, the KASH and SUN domain proteins, bridge the nuclear envelope, connecting the nuclear lamina to cytoskeletal components. PMID: 16481402
