Myosin heavy chain 3 (
MYH3) is a structural protein that affects muscle fiber type and its expression level is positively correlated with muscle fiber thickness.
FSS has been categorized as a specific subtype of DA type 2A in2006 [2] and is due to a mutation in embryonic myosin, mostly Myosin Heavy Chain 3 (
MYH3) [3].
Myosin-3 (MYH3) and plasma membrane calcium-transporting ATPase (ATP2B), or PMCA, also showed interactions with CIB4 protein.
Figure 7 also shows the interaction of myosin-3 (MYH3) with CIB4 protein.
Thus, SREBF1 is a master regulator which controls gene expression within the SREBF1 to FASN region via targeting transcriptional repressors of MPRIP, TCAP, and other muscle-related genes (BECN1, CACNB1, MYH2,
MYH3, and MYH13); one of these repressors BHLHB 2 maps near FASN [55].
The genetic basis was unravelled in 2006 with missense mutations in the motor domain of the embryonic myosin heavy chain
MYH3 gene, which encodes embryonic myosin, one of the proteins of the contractile complex of skeletal muscle cells [4].
Additionally, all AFSC lines presented low expression of mesoendodermal genes MIXL1, GATA6, SOX17, and FOXA1 and negative expression of mesoendodermal and ectodermal genes, including BRACH, PDGFRa, ACAN, OCN, MYOD,
MYH3, RELN, POU4F2, and FOXG1 (Supporting information Figure 1(c)).
The variants identified in DTD1.3ISA were filtered for known pathogenic mutations from the ClinVar database [7,8] in nine genes (TPM2, MYBPC1,
MYH3, TNNT3, TNNI2, PIEZO2, ECEL1, MYH8 and FBN2) that had previously been shown to be mutated in persons with DA (OMIM #108120).
The
MYH3 and MYH8 genes are up-regulated in the paretic leg 4.3-fold and 3.7-fold, respectively.