sarcospan; K-ras oncogene-associated protein; Kirsten-ras-associated protein (SSPN, KRAG)

Function

• component of the dystrophin-glycoprotein complex (DGC), a complex that spans the muscle plasma membrane & forms a link between the F-actin cytoskeleton & the extracellular matrix
• preferentially associates with the sarcoglycan subcomplex of the DGC

Compartment

• cell membrane; multi-pass membrane protein (putative)
• sarcolemma
• cell junction, synapse, postsynaptic cell membrane
• found in myotendinous junctions & in postsynaptic membrane of neuromuscular junctions
• sarcospan is lost in patients with complete or partial loss of sarcoglycans
• possibly the complete, tetrameric sarcoglycan complex is necessary for membrane targeting & localization of sarcospan

Alternative splicing

• named isoforms=2

Expression

• isoform 1 is expressed exclusively in heart & skeletal muscle
• isoform 2 is expressed in heart, skeletal muscle, thymus, prostate, testis, ovary, small intestine, colon & spleen

More general terms

• transmembrane 4 protein
• human longevity protein

Component of

• dystrophin associated protein complex (DPC)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=8082
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:8082
• OMIM: https://mirror.omim.org/entry/601599
• UniProt: http://www.uniprot.org/uniprot/Q14714.html