A novel mechanism for the translational regulation of creatine kinase during Xenopus oogenesis.

Format:

Book

Thesis/Dissertation

Author/Creator:

Cally, Steven James.

Contributor:

Holmes, Edward W., advisor.

University of Pennsylvania.

Language:

English

Subjects (All):

Cytology.

Molecular biology.

0307.

0379.

Penn dissertations--Cell and molecular biology.

Cell and molecular biology--Penn dissertations.

Local Subjects:

Penn dissertations--Cell and molecular biology.

Cell and molecular biology--Penn dissertations.

0307.

0379.

Physical Description:

96 pages

Contained In:

Dissertation Abstracts International 59-11B.

System Details:

Mode of access: World Wide Web.

text file

Summary:

Gene regulation during early Xenopus development is largely based on the selective translational recruitment of maternal messenger RNAs. Major shifts in the population of expressed messages occur at distinct developmental boundaries, such as oocyte maturation and fertilization; translational activation at these points in development is usually concomitant with transcript polyadenylation. However, the mechanisms underlying the translational activation of maternal messages prior to oocyte maturation are largely unknown. In this report, standard molecular biology techniques are used to examine the translational behavior of the Xenopus creatine kinase-IV (CK) maternal RNA. We demonstrate that this message is subject to a novel mechanism of translational activation in the growing oocyte. The CK maternal message reaches a steady state level by stage 2 of oogenesis. However, the expression of this not constant; it increases by greater than ten fold to a peak in stage 4, then returns to low levels in stages 5 and 6. The translational activation of this transcript is not associated with a change in transcript polyadenylation state nor in localization of the message within the oocyte. The highly conserved 3' untranslated region (UTR) of this message is sufficient to convey a translational advantage to a injected, heterologous transcript, implicating this region in the translational regulation of endogenous CK. This region is also capable of specifically competing translational activity from endogenous CK message in stage 4 oocytes, suggesting the involvement of a competable trans-factor(s) at this point in development. The CK 3' untranslated region binds 2 oocyte trans-factors in a stage-specific manner; the coincidence of these binding activities is concomitant with the peak of CK translation in stage 4. We propose a model by which the developing oocyte regulates the expression of creatine kinase, and discuss the implications of our observations to the current understanding of translational control during Xenopus development.

Notes:

Thesis (Ph.D. in Cell and Molecular Biology) -- University of Pennsylvania, 1998.

Source: Dissertation Abstracts International, Volume: 59-11, Section: B, page: 5703.

Adviser: Edward W. Holmes.

Local Notes:

School code: 0175.

ISBN:

9780599120471

Access Restriction:

Restricted for use by site license.