-transparent.png){kind=logo}
In fully grown Xenopus oocytes, the synthesis of beta-subunits is limiting for the formation of functional Na(+)-K(+)-adenosinetriphosphatase alpha/beta-complexes (Geering, K. FEBS Lett. 285: 189-193, 1991). In the present study, we show that during oocyte growth (from stage I to stage VI) alpha 1-, but not beta 1- or beta 3-isoform, mRNAs accumulate. In addition, beta-mRNAs are apparently sequestered in an untranslated pool in fully grown oocytes (stage VI). From fertilization to morulation, the total pools of alpha 1-, beta 1-, or beta 3-mRNAs vary little. Whereas polyadenylated [poly(A)+] alpha 1- and beta 3-isoform mRNAs did not change significantly, poly(A)+ beta 1-mRNA abundance increased three- to fourfold at morulation, accompanied by a parallel increase in beta 1-protein synthesis. After midblastula transition (i.e., at early gastrula) and during neurulation, poly(A)+ alpha 1- and beta 3-mRNAs accumulated rapidly, whereas poly(A)+ beta 1-mRNA accumulation was delayed by approximately 2 h, beginning only at early neurula. Our results indicate that 1) the abundance of poly(A)+ beta 1-mRNA is rate limiting during embryonic development for the assembly of alpha 1/beta 1-heterodimers, shown to be involved in the vectorial transport of sodium in kidney cells, and 2) the polyadenylation of beta 1-mRNA is a rate-limiting factor during morulation for the synthesis and assembly of new sodium pumps at the time of blastocoel fluid formation. The 3'-untranslated region of beta 1-mRNA (but not of alpha 1-mRNA) expresses cytoplasmic polyadenylation elements (CPEs) with the consensus sequence AXX-AUUUU(A/U)(A/U)(A/U). A role of CPE in the differential polyadenylation of alpha 1- and beta 1-mRNA is proposed.
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
May 1991,
Developmental biology,
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
December 1990,
Proceedings of the National Academy of Sciences of the United States of America,
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
June 1992,
The American journal of physiology,
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
July 1994,
The Journal of biological chemistry,
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
December 1997,
Biochimica et biophysica acta,
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
November 1980,
Bollettino della Societa italiana di biologia sperimentale,
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
February 1997,
Molecular reproduction and development,
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
October 1991,
Genomics,
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
December 1982,
Bollettino della Societa italiana di biologia sperimentale,
P Burgener-Kairuz, and
I Corthesy-Theulaz, and
A M Merillat, and
P Good, and
K Geering, and
B C Rossier
January 1990,
Developmental genetics,
