Chloride nucleotide-sensitive channel 1A (CLNS1A)

Chloride nucleotide-sensitive channel 1A (CLNS1A), also known as methylosome subunit pICln, is a multifunctional protein involved in regulating chloride ion flux for cell volume control, acting as part of ion channel activity in the plasma membrane, and serving as a chaperone for spliceosome assembly in the nucleus. It forms a methylosome complex with PRMT5 and MEP50 to modify Sm proteins, crucial for RNA splicing and genome stability. CLNS1A promotes cell proliferation and survival, modulates DNA repair pathways, and has been implicated in several oncogenic contexts, particularly by enhancing cellular resistance to chemotherapy through chloride channel activity and dysregulated methylation. High CLNS1A expression is correlated with poor prognosis and increased chemoresistance in cancers such as lung and breast cancer, and it is also involved in immune cell proliferation and autoimmunity. Therapeutic modulation remains challenging due to its essential cellular functions and wide involvement in critical cell processes.

Other names

Methylosome subunit pIClnCLCIIClnI(Cln)ClCIchloride conductance regulatory protein IClnchloride ion current inducer proteinreticulocyte pIClnCLNS1Bchloride channel regulatory proteinchloride channel, nucleotide sensitive 1A

Blockade of chloride channel activity to counteract drug resistance; Inhibition of protein-protein interaction with PRMT5/methylosome complex; Modulation of splicing machinery or epigenetic transcriptional activation