Synemin isoforms during mouse development: multiplicity of partners in vascular and neuronal systems.
The intermediate filament (IF) synemin gene encodes three IF proteins (H 180, M 150, L 41 kDa isoforms) with overlapping distributions. In the present study we analysed the mRNA and protein expression of each isoform in developing mouse embryos. Synemin M mRNA was present as early as E5 with vimentin and nestin. Synemin H was found later at E9 in the nervous system and mesodermic derivatives concomitantly with angiogenesis, somitogenesis and the migration of neural crest cells. Synemin L appeared later in neurons at E15. Furthermore, the synemin isoforms required different IF partners depending on the cell type to form filamentous structures. In endothelial cells, synemin H/M were found associated with vimentin and were absent in vimentin-null mice. In neurons of the peripheral nervous system of E15 embryos, synemin H/M or L were co-expressed with neurofilament, peripherin and internexin. In adult mice, our data support the existence of different subpopulations of neurons within the dorsal root ganglia: one composed of small neurons containing synemin H/M and peripherin, and another composed of large neurons containing synemin L and neurofilaments. Axons devoid of neurofilaments from mutant mice (NFHLacZ) showed an absence of the L isoform but contained H/M isoforms with peripherin.
Izmiryan
Araksya
A
UPMC Univ Paris 06, UMR 7079, F-75005, Paris, France.
Franco
Claudio Areias
CA
Paulin
Denise
D
Li
Zhenlin
Z
Xue
Zhigang
Z
D000818:Animals; D001808:Blood Vessels / Q000196:embryology / Q000378:metabolism*; D019521:Body Patterning / Q000235:genetics; D002478:Cells, Cultured; D018507:Gene Expression Regulation, Developmental; D007381:Intermediate Filament Proteins / Q000235:genetics* / Q000378:metabolism*; D007763:Lac Operon; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009420:Nervous System / Q000196:embryology / Q000378:metabolism; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D014018:Tissue Distribution; D014162:Transfection; D014746:Vimentin / Q000235:genetics / Q000378:metabolism
D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D014746:Vimentin; C430456:desmuslin