Phosphatase Subfamily DSP23

Phosphatase Classification: Fold CC1: Superfamily CC1: Family DSP: Subfamily DSP23

summary...

Evolution

DSP23 is found in metazoan but lost in nematodes and most arthropods (unpublished data from gOrtholog) has a single member in human, DUSP23.

Domain

DSP23 has a single domain, the phosphatase domain. Actually, it is the shortest within DSP family.

Function

Laforin is a glucan phosphatase [1, 2].

laforin is also a phosphatase of muscle glycogen synthase (GS1) in polyglucosan bodies (PBs). In Lafora disease (LD), the deficiency of either laforin or E3 ligase malin causes massive accumulation of less-branched glycogen inclusions, known as Lafora bodies, also called polyglucosan bodies (PBs), in several types of cells including neurons. Once GS1-synthesized polyglucosan accumulates into PBs, laforin recruits malin to the PBs where laforin dephosphorylates, and malin degrades the GS1 in concert with GPBB and AGL1, resulting in a breakdown of polyglucosan [3]. Laforin also dephosphorylates Ser 9 of Glycogen synthase kinase 3 [4].

Laforin also as an adaptor protein involved in several physiological pathways [5]. For instance, the complex of laforin and malin modules protein phosphatase 1 regulatory subunit PPP1R3D via ubiquitination [6]. See [5] for details.

Links

Human DUSP23 page in Phosphatome.Net database.