| Aspect | Key findings | Evidence type | Primary source with year/DOI/URL |
|---|---|---|---|
| identity/structure | **pgl-2 corresponds to C. elegans ORF B0523.3**, encoding a predicted **532-aa PGL family protein** related to PGL-1; its N-terminal 414 aa share **34% identity / 67% similarity** with PGL-1. PGL-2 is described as a **novel P-granule protein** and, unlike PGL-1/PGL-3, **lacks an RGG box** in the reported analysis. (pqac-00000004, pqac-00000000) | Sequence analysis; cDNA/mRNA characterization; comparative protein analysis | Kawasaki et al., 2004. *Genetics* 167:645-661. DOI: 10.1534/genetics.103.023093. URL: https://doi.org/10.1534/genetics.103.023093 |
| localization | PGL-2 is a **component of germline P granules/germ granules** in **postembryonic germ cells** and was reported as **undetectable in embryos** under the authors’ staining conditions. It localizes to **perinuclear P granules** in the germ line. (pqac-00000002, pqac-00000001, pqac-00000003, pqac-00000005) | Immunostaining with anti-PGL-2 antibodies; germline localization studies; review synthesis | Kawasaki et al., 2004. *Genetics* 167:645-661. DOI: 10.1534/genetics.103.023093. URL: https://doi.org/10.1534/genetics.103.023093; Sundby et al., 2021. *Trends Cell Biol.* DOI: 10.1016/j.tcb.2020.12.012. URL: https://doi.org/10.1016/j.tcb.2020.12.012 |
| interactions | PGL-2 shows **physical association with other PGL proteins**: **PGL-1–PGL-2** interaction was identified in **yeast two-hybrid**, and **PGL-2 associates with PGL-1 and PGL-3** in **GST pull-down / in vitro binding assays**. By contrast, the reported specific interaction with the germline eIF4E **IFE-1** was for **PGL-1**, not PGL-2. (pqac-00000004, pqac-00000001, pqac-00000003) | Yeast two-hybrid; GST pull-down; protein interaction assays | Kawasaki et al., 2004. *Genetics* 167:645-661. DOI: 10.1534/genetics.103.023093. URL: https://doi.org/10.1534/genetics.103.023093 |
| genetic phenotypes | A **pgl-2 deletion allele (bn123)** predicted to truncate the protein after about residue 188 behaved as a likely **strong loss-of-function/null**. **pgl-2 single mutants showed no obvious germline defects or significant sterility** under laboratory conditions, and **pgl-2; pgl-1 double mutants did not enhance pgl-1 sterility**. In contrast, **pgl-1; pgl-3** double mutants showed strong sterility/embryonic defects, indicating PGL-2 is not the principal redundant partner of PGL-1. (pqac-00000001, pqac-00000002, pqac-00000006) | Deletion mutant genetics; fertility assays; double/triple mutant analysis | Kawasaki et al., 2004. *Genetics* 167:645-661. DOI: 10.1534/genetics.103.023093. URL: https://doi.org/10.1534/genetics.103.023093; Spike et al., 2008. *Genetics* 178:1973-1987. DOI: 10.1534/genetics.107.083469. URL: https://doi.org/10.1534/genetics.107.083469 |
| pathway/assembly dependencies | Each PGL protein, including PGL-2, can **localize to P granules independently of the other PGLs**, but efficient recruitment/retention requires **GLH-1**, placing GLH-1 upstream in P-granule assembly. Loss of GLH-1 causes **partial dispersal of PGL proteins including PGL-2**. PGL-2 therefore functions within the **P-granule assembly/localization network** rather than as a sole determinant of granule formation. (pqac-00000003, pqac-00000001, pqac-00000007) | Genetics; localization dependency analysis; immunostaining; pathway interpretation | Kawasaki et al., 2004. *Genetics* 167:645-661. DOI: 10.1534/genetics.103.023093. URL: https://doi.org/10.1534/genetics.103.023093; Amini, 2009 thesis/report on P granule function (as cited in evidence) |
| functional interpretation | Current evidence supports PGL-2 as a **structural/assembly-associated germ-granule protein** involved in **post-transcriptional germline RNP biology**, not as a characterized enzyme. **No direct biochemical or enzymatic activity has been demonstrated for PGL-2** in the cited evidence. Relative to family members, **PGL-1 is most critical**, **PGL-3 is the key redundant partner of PGL-1**, and **PGL-2 appears largely dispensable under standard laboratory conditions**, though it may contribute to overall P-granule robustness/fertility in some contexts. (pqac-00000000, pqac-00000002, pqac-00000006) | Genetic inference; family comparison; review/primary synthesis | Kawasaki et al., 2004. *Genetics* 167:645-661. DOI: 10.1534/genetics.103.023093. URL: https://doi.org/10.1534/genetics.103.023093; Spike et al., 2008. *Genetics* 178:1973-1987. DOI: 10.1534/genetics.107.083469. URL: https://doi.org/10.1534/genetics.107.083469 |


*Table: This table summarizes experimentally supported findings about C. elegans pgl-2/PGL-2, including identity, localization, interaction partners, mutant phenotypes, and placement in the P-granule assembly pathway. It is useful as a compact evidence map showing what is directly known versus what remains inferential.*