Sm-like protein Lsm4 (IPR034101)

Short name: Lsm4

Overlapping homologous superfamilies

Domain relationships


This entry represents Sm-like protein Lsm4. It could be found in the nuclear Lsm2-8 complex or in the cytoplasmic Lsm1-7 complex.

The Lsm2-8 complex associates with multiple snRNP complexes containing the U6 snRNA (U4/U6 snRNP, U4/U6.U5 snRNP, and free U6 snRNP). It binds and stabilizes the 3'-terminal poly(U) tract of U6 snRNA and facilitates the assembly of U4-U6 di-snRNP and U4-U6-U5 tri-snRNP [PMID: 22615807, PMID: 15916535, PMID: 24240276]. The Lsm1-7 complex associates with deadenylated mRNA and promotes decapping in the 5'-3' mRNA decay pathway [PMID: 22615807, PMID: 10801455].

The Sm and the Lsm proteins, characterised by the Sm-domain, have RNA-related functions. The Sm heptamer ring associates with four (U1, U2, U4, U5) snRNPs, while Lsm2-8 heptamer associates with the U6 snRNP. Another Lsm heptameric complex, Lsm1-7, which differs from Lsm2-8 by one Lsm protein, functions in mRNA decapping, a crucial step in the mRNA degradation pathway [PMID: 24513854].

GO terms

Biological Process

GO:0000398 mRNA splicing, via spliceosome
GO:0000956 nuclear-transcribed mRNA catabolic process

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.