Table 1.
Examples of the various biomolecular condensates and their characteristics
| Organelle | Year of discovery | Key components | Size | Associated processes | Reference | |
|---|---|---|---|---|---|---|
| Key proteins | RNA | |||||
| Nucleolus |
1774 1835 1837 |
Fibrillarin, nucleophosmin | rRNA | 6 µm | Ribosome biogenesis | [20, 21, 190, 319, 320] |
| Cajal bodies |
1903 1969 |
Coilin, survival motor neuron protein (SMN1) |
snRNA snoRNA |
0.3–1.0 µm | Assembling spliceosomal small nuclear ribonucleoproteins | [77, 180, 321, 322] |
| PML bodies | 1960 | PML, SUMO-1, Sp100 | None | 0.1–1.0 µm | Apoptotic signaling anti-viral defense transcription regulation | [194, 258, 323] |
| Nuclear speckles | 1910 | SRSF1, SRSF2, SPOP |
Poly(A) + RNA; lncRNA MALAT1 |
0.5 µm to several µm | mRNA splicing | [186, 283, 321] |
| Cleavage bodies | 1999 | DDX1, CstF-64 |
(Pre-)U-snRNAs; 7SK snRNA C/D & H/ACA box snoRNAs TERC |
0.3–1 µm | Processing of 3′-end of pre-mRNA | [182, 324] |
| Histone locus bodies (HLBs) | 1960 | FLASH, LSM11, NPAT |
Histone mRNAs U7 snRNA U2 snRNA Y3/Y3** ncRNA |
0.3–1.0 µm | Processing of histone pre-mRNA | [183, 325] |
| Nuclear gems | 1996 | SMN, Sm proteins | None | 0.1 µm (A, C and E) or 30 μm (B, D and F) | Assembly of the spliceosomal small nuclear ribonucleoproteins (snRNPs) | [184, 185, 326] |
| Oct1/PTF/transcription (OPT) domains | 1998 | 53PB1, γH2AX, MDC1, OPT | None | 5–25 µm | Maintenance of the genome integrity | [191, 327] |
| Balbiani body* |
1845 1887 |
Bucky ball, Xvelo, Hba1, Hbg, Cup and Orb | mRNA | Up to 50 µm | Embryonic determinant that specifies germline identity by forming germ plasm (frogs and fish). For other species, Bb function(s) remains either highly hypothetical or completely unknown | [206, 328, 329] |
| Paraspeckles | 2002 |
FUS NONO SFPQ HNRNPK DAZAP1 RBM14 HNRNPH3 |
lncRNA NEAT1 | 0.5–1 µm | Storage of certain RNAs | [193, 330] |
| Polycomb bodies (PcG bodies) | 1998 | Polycomb-group proteins, PcG, Bmi1 | None | 0.2–1.5 µm | Gene silencing | [195, 331] |
| Sam68 nuclear bodies (SNBs) | 1999 |
Sam68 DBC1 SLM-1 T-STAR hnRNP L |
arcRNA | 0.3–1.0 μm | SNB may act as the regulatory factory of coupled transcription-splicing events | [192, 332–334] |
| P-bodies | 1997 |
Dcp1a Lsm proteins Rck/p54 GW182 |
Translationally repressed mRNA | 5.1–15 µm | mRNA storage and translational regulation | [175, 176, 335, 336] |
| Stress granules | 1999 |
FUS hnRNPA1 |
Poly-(A) + mRNA associated with PABP | 0.1–2.0 μm | mRNA decay and silencing | [177, 336, 337] |