Myosin Binding Protein-C Slow: An Intricate Subfamily of Proteins

Figure 2

RT-PCR analysis using cDNA generated from developing and adult rat extensor digitorum longus (EDL), flexor digitorum brevis (FDB), tibialis anterior (TA), gastrocnemius (gastroc), quadriceps (quad) and soleus skeletal muscles and primer sets designed to flank the NH₂-terminal (a), Ig7 (b), and COOH-terminal (c) insertions. A schematic representation of the amplified region is shown in the upper left corner of each panel. White and grey ovals depict Ig and FN-III domains, respectively, while the 3^ UTR is shown as a black line. The zig-zag lines denote the three novel insertions. In each amplification reaction, the top band corresponds to transcripts that include the insertion of interest, whereas the bottom band corresponds to transcripts that lack it. (a): All skeletal muscles tested contain a mixed population of MyBP-C slow variants that contain and lack the NH₂-terminal insertion, as indicated by the presence of two amplification products. (b): On the contrary, only soleus and developing myotubes express transcripts that include the Ig7 insertion. (c): With the exception of quadriceps muscle that only contains MyBP-C slow variants that lack the COOH-terminal insertion, all other muscles examined contain a mixed pool of transcripts that carry and lack the novel COOH-terminal insertion.

(a)

(b)

(c)