Expression of the internal calcium pump in pregnant rat uterus.
Uterine contraction to agents such as oxytocin during labour may utilize Ca2+ sequestered by Ca2+ pump into the sarcoplasmic reticulum (SR). Uterus expresses the SR Ca2+ pump gene SERCA2 as the mRNA splice which encodes the protein SERCA2b. The expression of SERCA2 mRNA and protein was monitored in uteri of day 15 pregnant and delivering rats. The ratio of SERCA2 mRNA to 28S RNA increased by 20% from day 15 to delivery. SERCA2 protein examined by two antibodies increased by 54-55%. Ca2+ dependent acylphosphate intermediate of 115 kD corresponding to SERCA2 also increased 72% during this period. Thus, there is an increase in the SERCA2 expression from day 15 to delivery.
Department of Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
I
I
Khan
T
T
Tabb
R E
RE
Garfield
L R
LR
Jones
V P
VP
Fomin
S E
SE
Samson
A K
AK
Grover
D000215:Acylation; D000818:Animals; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases; D005260:Female; D005786:Gene Expression Regulation; D007743:Labor, Obstetric / Q000378:metabolism; D008861:Microsomes / Q000737:chemistry; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000096:biosynthesis*; D009215:Myometrium / Q000378:metabolism*; D010710:Phosphates / Q000032:analysis; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar / Q000378:metabolism
D009124:Muscle Proteins; D010710:Phosphates; D011257:Pregnancy Proteins; D012333:RNA, Messenger; D000252:Calcium-Transporting ATPases; D002118:Calcium