| Aspect | Evidence summary | Evidence type | Key citations |
|---|---|---|---|
| Identity/domain | The target is **C. elegans meg-4 / C36C9.1 / MEG-4**, a close paralog of MEG-3 with **71% identity**. Evidence supports MEG-4 as a **serine-rich, low-complexity, largely intrinsically disordered protein** (~570/832 aa, 69% predicted disordered). Later work aligned a conserved **HMG-like motif** in MEG-4 with the motif in MEG-3/GCNA proteins. The literature snippets reviewed **do not support a J-domain/Hsp40 assignment** for MEG-4. | Inference from sequence prediction + comparative/domain analysis; supported by genetics-focused primary literature | (pqac-00000001, pqac-00000011, pqac-00000017, pqac-00000018) |
| Localization | MEG-4 is maternally provided and associates with **embryonic P granules/germ plasm** from the **1-cell to ~100-cell stage**, segregating with the **P lineage**. A CRISPR **3×FLAG-tagged MEG-4** was used for localization. MEG-4 is not reported in adult gonad perinuclear granules, and MEG proteins can persist in granules longer than PGL proteins during disassembly; MEG-positive/PGL-negative granules were observed. | Cell biology + genetics | (pqac-00000003, pqac-00000013) |
| Molecular/biophysical role | MEG-4 acts **redundantly with MEG-3** as a primary factor for **assembly of embryonic P granules** and enrichment of P-granule-associated mRNAs in germline blastomeres. Loss of meg-3/4 prevents proper localization of **PGL droplets** and condensation of P-granule mRNAs. The direct biophysical work is stronger for MEG-3, but the evidence supports MEG-4 participating in the same **condensate/phase-separation scaffold system**. | Genetics + cell biology; partial inference from paralogy and shared phenotypes | (pqac-00000000, pqac-00000002, pqac-00000006, pqac-00000007, pqac-00000016) |
| Pathways/regulators | Genetic epistasis places meg-4 with meg-3 **downstream of MBK-2 and PPTR-1/2** in controlling the balance between P-granule assembly and disassembly. In **mbk-2; meg-3 meg-4** embryos, granules still fail to assemble, showing MEG-3/4 are required even when disassembly is blocked. Direct phosphorylation was shown for MEG-1 and MEG-3, but **direct biochemical phosphorylation evidence for MEG-4 was not shown** in the cited snippets. | Genetics with limited biochemical inference | (pqac-00000000, pqac-00000003, pqac-00000004, pqac-00000010, pqac-00000014) |
| Mutant/RNAi phenotypes | **meg-4 single mutants** show only a **slight reduction** in P-granule number, whereas **meg-3 meg-4 double mutants** have severe embryonic P-granule assembly defects and symmetric segregation of nos-2 RNA. Perinuclear P granules reappear later in PGCs/L1, indicating a stage-specific requirement. **meg-3 meg-4** animals show partial sterility, while adding loss of other meg genes can cause severe germline proliferation defects and complete sterility. | Genetics + developmental cell biology | (pqac-00000000, pqac-00000002, pqac-00000005, pqac-00000010, pqac-00000012, pqac-00000018) |
| Key quantitative data | Reported values include: **MEG-4 832 aa**, **69% predicted disorder (570/832 aa)**; **MEG-3/MEG-4 71% identical**; in **meg-3 meg-4** zygotes, total P granules during first mitosis are about **11% of wild type**; adult sterility is about **27-30%** for **meg-3 meg-4**, with **~70% fertile**; **meg-1 meg-3 meg-4** mutants are **100% sterile** and larvae can have **<10 germ cells**. | Quantitative genetics/cell biology; sequence-based inference | (pqac-00000001, pqac-00000002, pqac-00000006, pqac-00000007, pqac-00000010, pqac-00000011) |


*Table: This table summarizes the evidence-supported functional annotation of C. elegans meg-4/MEG-4, including identity, localization, biological role, regulatory context, and mutant phenotypes. It is restricted to claims directly supported by the cited evidence snippets and highlights where conclusions are based on inference rather than direct MEG-4 biochemistry.*