Sarcoglycan subcomplex expression in normal human smooth muscle.
The sarcoglycan complex (SGC) is a multimember transmembrane complex interacting with other members of the dystrophin-glycoprotein complex (DGC) to provide a mechanosignaling connection from the cytoskeleton to the extracellular matrix. The SGC consists of four proteins (alpha, beta, gamma, and delta). A fifth sarcoglycan subunit, epsilon-sarcoglycan, shows a wider tissue distribution. Recently, a novel sarcoglycan, the zeta-sarcoglycan, has been identified. All reports about the structure of SGC showed a common assumption of a tetrameric arrangement of sarcoglycans. Addressing this issue, our immunofluorescence and molecular results showed, for the first time, that all sarcoglycans are always detectable in all observed samples. Therefore, one intriguing possibility is the existence of a pentameric or hexameric complex considering zeta-sarcoglycan of SGC, which could present a higher or lower expression of a single sarcoglycan in conformity with muscle type--skeletal, cardiac, or smooth--or also in conformity with the origin of smooth muscle.
Anastasi
Giuseppe
G
Department of Biomorphology and Biotechnologies, University of Messina, Via Consolare Valeria, 1 IT-98125, Messina, Italy.
Cutroneo
Giuseppina
G
Sidoti
Antonina
A
Rinaldi
Carmen
C
Bruschetta
Daniele
D
Rizzo
Giuseppina
G
D'Angelo
Rosalia
R
Tarone
Guido
G
Amato
Aldo
A
Favaloro
Angelo
A
D000328:Adult; D005455:Fluorescent Antibody Technique; D041981:Gastrointestinal Tract / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D046912:Multiprotein Complexes / Q000096:biosynthesis; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D009130:Muscle, Smooth / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D009928:Organ Specificity; D021122:Protein Subunits / Q000096:biosynthesis; D012137:Respiratory System / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D049031:Sarcoglycans / Q000096:biosynthesis*; D014566:Urogenital System / Q000378:metabolism
D046912:Multiprotein Complexes; D021122:Protein Subunits; D049031:Sarcoglycans