Isoform switching of the sarco(endo)plasmic reticulum Ca2+ pump during differentiation of BC3H1 myoblasts.
We have studied the expression of the gene 2 for the sarco(endo)plasmic reticulum Ca2+ pump (SERCA2) in BC3H1 cells. Myogenic differentiation not only activated the SERCA2 expression but it also induced an isoform switch. Undifferentiated myoblasts only expressed the SERCA2b isoform (non-muscle) whereas differentiated myocytes predominantly contained the SERCA2a isoform (cardiac/slow skeletal muscle). The isoform switch was documented by immunoblot analysis with isoform-specific antibodies. This observation was confirmed at the mRNA level by using antisense RNA probes specific for class 1 (SERCA2a) or class 2 (SERCA2b) messengers. The expression of the SERCA2a isoform after differentiation was accompanied by a decreased sensitivity of the Ca2+ uptake in permeabilized cells to the Ca2+ pump inhibitor thapsigargin.
de Smedt
H
H
Laboratorium voor Fysiologie, Katholieke Universiteit Leuven, Belgium.
Eggermont
J A
JA
Wuytack
F
F
Parys
J B
JB
Van den Bosch
L
L
Missiaen
L
L
Verbis
J
J
Casteels
R
R
D000818:Animals; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D009132:Muscles / Q000166:cytology / Q000201:enzymology*; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D013729:Terpenes / Q000494:pharmacology; D019284:Thapsigargin
D007527:Isoenzymes; D013729:Terpenes; D019284:Thapsigargin; D000252:Calcium-Transporting ATPases; D002118:Calcium