TABLE 1.

Functions of the core U5 snRNP proteins, S. cerevisiae homologues and their association with retinitis pigmentosa, craniofacial disorders, or cancer.

U5 snRNP protein	Homologue in S. cerevisiae	Function in spliceosome	Retinitis pigmentosa	Craniofacial disorder	Cancer
TXNL4A	Dib1p	Prevents premature spliceosome activation?	No	Yes	No
SNRNP40	None	Protein-protein interaction, important for assembly or stability of U4/U6.U5 tri-snRNP? Function not well-characterised	No	No	Yes
CD2BP2/U5-52K	Snu40p	Interacts with PRPF6 and TXNL4A, not part of the tri-snRNP	No	No	No
DDX23/PRPF28	Prp28p	DEAD-box helicase, required for spliceosome B formation although function not well-characterised	No	No	Yes
PRPF6	Prp6	Assembly of tri-snRNP, molecular bridge between U5 snRNP and U4/U6 snRNP	Yes	No	Yes
PRPF8	Prp8p	Assembly of U5 snRNP, regulation of SNRNP200, forms catalytic centre of spliceosome	Yes	No	Yes
SNRNP200	Brr2p	Unwinding of U4/U6 snRNA duplex, activation of spliceosome	Yes	No	No
EFTUD2	Snu114p	Regulation of SNRNP200, regulation of spliceosome dissociation	No	Yes	Yes