Table I Proteins regulated by activin A signaling in the ECM. ECM was isolated at the onset of mineralization from SILAC labeled cultures and protein regulation was determined by mass spectrometry measurements. Ratios are averages of reciprocal SILAC experiments. A = Activin A; V = Vehicle. # peptides = minimum number of unique peptides identified for the protein. Ratio count = number of SILAC pairs used for quantitation. From the 293 proteins identified in the ECM 104 were found to be over 1.5-fold regulated but only the 20 strongest regulated proteins are shown (see supplementary Table 1 for the complete list of proteins identified and respective regulation)
#Protein nameIPI identifierGene symbolRatio A/V# PeptidesRatio count
>1.5-fold UP-regulated by activin A
    1Collagen alpha-1(XII) chainIPI00329573COL12A12.665289
    2Developmentally-regulated endothelial cell locus 1 proteinIPI00306046DEL12.291116
    3CFR-1IPI00414717CFR12.241011
    4Basement-membrane protein 40IPI00014572ON2.2024
    5FN1 proteinIPI00845263FN12.112357
    6Breast epithelial antigen BA46IPI00966900MFGE82.07226
    7cDNA FLJ58980, highly similar to Sideroflexin-3IPI00871988hCG_246612.0123
    8130 kDa leucine-rich proteinIPI00783271LRP1302.00612
    9Fibrillin-1IPI00328113FBN1.971319
    10CD49 antigen-like family member EIPI00306604FNRA1.93716
>1.5-fold DOWN-regulated by activin A
    1cDNA, FLJ95012, highly similar to Homo sapiens UDP-glucose pyrophosphorylase 2IPI00873223UGP20.2867
    2Glucose phosphomutase 1IPI00219526PGM10.3044
    3UDP-glucose 6-dehydrogenaseIPI00031420UGDH0.3023
    470 kDa laminIPI00021405LMN10.3169
    5Collapsin response mediator protein 2IPI00257508CRMP20.3156
    6Cell migration-inducing gene 10 proteinIPI00169383MIG100.341222
    7Triosephosphate isomeraseIPI00465028hCG_259360.3469
    8CalgizzarinIPI00013895MLN700.3423
    9BPG-dependent PGAM 1IPI00549725CDABP00060.3555
    106-phosphogluconate dehydrogenase, decarboxylatingIPI00219525PGD0.3754