ICln (IPR003521)

Short name: ICln

Overlapping homologous superfamilies


Family relationships


ICln, known as methylosome subunit pICln or chloride conductance regulatory protein ICln, owes these different names to its function in multiple regulatory pathways [PMID: 16734741] as different as ion permeation, ribonucleoprotein biosynthesis and cytoskeletal organisation [PMID: 9556550]. ICln can be identified both in the cytosol and in the cellular membrane, where it functions as a chloride current regulator and is important in regulating volume decrease after cellular swelling [PMID: 20573047, PMID: 15760659, PMID: 17138647, PMID: 19471107].

pLCln also functions as a Sm chaperone in the stepwise snRNP assembly process [PMID: 11747828]. snRNPs is a RNA-protein complex esessential to the removal of introns from pre-mRNA [PMID: 19520849, PMID: 10330151]. In humans, the core of snRNPs is composed of seven Sm proteins bound to snRNA. pLCln tethers the hetero-oligomers SmD1/D2 and SmE/F/G into a ring-shaped 6S complex, which subsequently docks onto the SMN complex. The SMN complex then removes pICln and enables the transfer of pre-assembled Sm proteins onto snRNA [PMID: 23333303]. Consistent with the role of human pICln, the orthologue from S. pombe is required for optimal production of the spliceosomal snRNPs and for efficient splicing [PMID: 24298023].

GO terms

Biological Process

GO:0006884 cell volume homeostasis
GO:0006821 chloride transport
GO:0000387 spliceosomal snRNP assembly

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005829 cytosol
GO:0034709 methylosome
GO:0034715 pICln-Sm protein complex
GO:0005886 plasma membrane

Contributing signatures

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