FIGURE 3.

Pregnancy regulates the expression of SMTNL1 and MYPT1 in striated and smooth muscle. A, pregnancy and pseudopregnancy induce expression of SMTNL1 severalfold in striated muscle n = 5 ± S.E. p < 0.05. The inset below shows representative example of Western blot data. M, male expression levels. B, pregnancy induces significant expression of SMTNL1 relative to plantarus muscle in vascular (aorta) and uterine smooth muscle. Data shown are from day 0 and day 14 of pregnancy. Groups not connected by the same letter are significantly different n = 4 ± S.E., GLM with Tukey-test, p < 0.01. The inset below shows representative Western blots. C, pregnancy and SMTNL1 deletion induces MYPT1 expression in striated and smooth muscles n = 4 ± S.E., p < 0.05. The insets below show representative Western blots. D, upper panels show black and white images of the effects of pregnancy on MYPT1 and SMTNL1 expression in Type 2a. Lower panels show immunofluorescent images of SMTNL1 localization in uterus and aorta from control and pregnant WT and smtnl1^−/− mice by SMTNL1 (green). Images are a representative set of n = 4 experiments. Scale bars represent 20 μm. E, MYPT1 and PP1C expression are induced in striated muscle from pregnant women under going C-section compared non-pregnant women undergoing hysterectomy. Biopsy samples were taken from the abdominus rectus muscles and processed for quantitative Western blot analysis with the indicated antibodies, n = 5 ± S.E. p < 0.05. Representative Western blots are shown below.