OBSCN
Function
Structural component of striated muscles which plays a role in myofibrillogenesis. Probably involved in the assembly of myosin into sarcomeric A bands in striated muscle (PubMed:11448995, PubMed:16205939). Has serine/threonine protein kinase activity and phosphorylates N-cadherin CDH2 and sodium/potassium-transporting ATPase subunit ATP1B1 (By similarity). Binds (via the PH domain) strongly to phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2) and phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2), and to a lesser extent to phosphatidylinositol 3-phosphate (PtdIns(3)P), phosphatidylinositol 4-phosphate (PtdIns(4)P), phosphatidylinositol 5-phosphate (PtdIns(5)P) and phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) (PubMed:28826662).
Involvement in disease
Rhabdomyolysis 1
RHABDO1
An autosomal recessive disorder characterized by severe and recurrent rhabdomyolysis, usually with onset in the teenage years. Some of the episodes may be triggered by exercise or heat; others occur spontaneously. Rhabdomyolysis is the rapid breakdown of damaged or injured skeletal myofibres and may require intensive care management. Muscle breakdown results in release of myofibrillar content into the extracellular space and circulation, resulting in hyperCKemia (hyperCK) and myoglobinuria. RHABDO1 patients may have a history of myalgia and muscle cramps that precede the initial rhabdomyolysis episodes.
None
Disease susceptibility is associated with variants affecting the gene represented in this entry.
A chromosomal aberration involving OBSCN has been found in Wilms tumor. Translocation t(1;7)(q42;p15) with PTHB1.
Post-translational modifications
Autophosphorylated by protein kinase domains 1 and 2.
Sequence Similarities
Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family.
Cellular localization
- Isoform 3
- Cytoplasm
- Myofibril
- Sarcomere
- M line
- Cytoplasm
- Myofibril
- Sarcomere
- Z line
- In differentiating skeletal muscle cells, isoform 3 primarily localizes to the sarcomeric M-line and less frequently to the Z-disk (PubMed:12527750). Isoform 3 colocalizes with ANK1 isoform Mu17/ank1.5 at the M-line in differentiated skeletal muscle cells (PubMed:12527750).
- Cytoplasm
- Myofibril
- Sarcomere
- M line
- Cytoplasm
- Myofibril
- Sarcomere
- Z line
- Cell membrane
- Sarcolemma
- Nucleus
- Colocalizes with CDH2 and ATP1B1 to the sarcolemma and to intercalating disks in cardiac muscles. Colocalizes with ATP1B1 to M line and Z line in cardiac muscles.
Alternative names
KIAA1556, KIAA1639, OBSCN, Obscurin, Obscurin-RhoGEF, Obscurin-myosin light chain kinase, Obscurin-MLCK