synemin; desmuslin (SYNM, DMN, KIAA0353, SYN)

Function: - intermediate filament type-6 - role within the muscle cell cytoskeleton - forms heteropolymeric intermediate filaments (IFs) with desmin &/or vimentin - via its interaction with cytoskeletal proteins: a) alpha-dystrobrevin b) dystrophin c) talin-1 d) utrophin e) vinculin, is able to link these heteropolymeric IFs to adherens-type junctions, such as to the costameres, neuromuscular junctions, & myotendinous junctions within striated muscle cells - interacts with GFAP & VIM (putative) - isoform 1 interacts with TLN1 & VCL - isoform 2 interacts with DES & DTNA - isoform 1 & isoform 2 interact with DMD & UTRN Structure: - belongs to the intermediate filament family Compartment: - cytoplasm, cytoskeleton. cell junction, adherens junction - there are at least two distinct SYNM subpopulations, one in which SYMN interacts with DES within the Z-lines, & another in which it interacts with both DTNA & DES at the costamere Alternative splicing: named isoforms=3 Expression: - isoform 2 is strongly detected in adult heart, fetal skeletal muscles & fetal heart - isoform 1 is weakly detected in fetal heart & also in fetal skeletal muscle - isoform 1 & isoform 2 are detected in adult bladder (at protein level) - the mRNA is predominantly expressed in heart & muscle with some expression in brain which may be due to tissue-specific isoforms - in lens - first detected at 16 weeks when expression is weakly & uniformly distributed - subsequently, expression becomes much stronger in the epithelium of the anterior part at 25 weeks & later - in retina - weakly expressed at 15 weeks in the nerve fiber layer & ganglion cell layer - from 25 weeks onwards, much stronger expression is observed in the endfeet of Mueller cells, the nerve fiber layer, & ganglion cell layer - much lower expression is observed in a minor subpopulation of cells in the inner cell layer - at 30 & 36 weeks, expression remains in the neural retina, & subsequently becomes stronger in the nerve fiber layer, ganglion cell layer, & inner cell layer & is decreased in Mueller cells - at 36 weeks, also expressed at the external border of the outer nuclear layer (at protein level)

General

intermediate filament protein phosphoprotein

Properties

SIZE: entity length = 1565 aa MW = 173 kD COMPARTMENT: cytoplasm MOTIF: Head {1-10} DMD/UTRN interaction {11-320} MOTIF: Rod {11-300} Coil 1A {11-49} Linker 1 {50-58} Coil 1B {59-163} Linker 12 {164-186} Coil 2 {187-300} Tail {301-1565} MOTIF: Ser phosphorylation site {S429} Thr phosphorylation site {T598} Ser phosphorylation site {S653} Ser phosphorylation site {S1044} Ser phosphorylation site {S1049} TLN1/VCL interaction {1152-1463} Ser phosphorylation site {S1181} Ser phosphorylation site {S1184} DMD/UTRN interaction {1244-1563} Ser phosphorylation site {S1435}

Database Correlations

OMIM 606087 UniProt O15061 Pfam PF00038 Entrez Gene 23336 Kegg hsa:23336

References

UniProt :accession O15061