Phase separation in biology; functional organization of a higher order

Table 1 Protein and RNA composition of membrane-less organelles

Organelle	Biological role	Protein	Domains/Motifs	RNA
Nucleolus	Ribosome biogenesis in nucleus	Fibrillarin	RGG box [133]	rRNA [8]
Nucleolus	Ribosome biogenesis in nucleus	Nucleolin	RRMs; RGG box [67]	rRNA [8]
Paraspeckles	Regulation of gene expression in nucleus	PSPC1	RRMs; Coil [2]	ncRNA NEAT1 (Menε/β); Ctn [2, 19]
		NONO/P54NRB	RRMs; Coil [2]
		SFPQ/PSF	RRMs; Coil [2]
Nuclear speckles	Regulation of gene expression via storage of splicing factors	SRSF1	RRMs; RS [134]	Poly(A)⁺ RNA; lncRNA MALAT1 [3, 134]
Cajal bodies	Regulation of snRNP maturation	Coilin	Coiled-coil [23]	snRNA; snoRNA [4, 135]
Cajal bodies	Regulation of snRNP maturation	SMN	Coiled-coil [23]	snRNA; snoRNA [4, 135]
PML bodies	Regulation of transcription and protein storage	PML	Coiled-coil [12]	None [11, 29]
Germ granules	Regulation of mRNA translation in the cytoplasm of germ cells	GLH-1, GLH-2, GLH-4	FG [74]	Developmentally regulated maternal mRNAs (nos-1, pos-1, mex-1, skn-1 , gld-2) [74, 136]
		PGL-1, PGL-3	RGG [63]
		DDX4	FG; RG [48]
		LAF-1	RGG box [47]
P bodies	mRNA processing and decay	Pdc1	HLM; Coiled-coil [49]	mRNA [31]
		Dcp2	HLM [49]
		Edc3	LSm; FDF [49]
Stress granules	Storage of translationally stalled mRNA and proteins of the translational machinery	FUS	RRM; RGG box; [G/S]Y[G/S] [50, 137]	Poly-(A)⁺ mRNA associated with PABP [30]
Stress granules		hnRNPA1	RRM; RGG box; [G/S]Y[G/S] [50]	Poly-(A)⁺ mRNA associated with PABP [30]

ISSN: 1478-811X