Identification and characterization of the gene encoding human cytoplasmic polyadenylation element binding protein

Area of Science:

• Molecular Biology
• Developmental Biology
• RNA Biology

Background:

• Human oocyte maturation occurs without gene transcription.
• Regulated translation of maternal mRNAs controls oocyte maturation and early development in model organisms.
• Cytoplasmic polyadenylation, an increase in poly(A) tail length, stimulates maternal mRNA translation during maturation.

Purpose of the Study:

• To investigate the mechanism of mRNA translational control in human oocytes.
• To clone and characterize human proteins involved in cytoplasmic polyadenylation.

Main Methods:

• Cloning of a human cytoplasmic polyadenylation element binding (hCPEB) protein.
• Analysis of RNA binding activity.
• Investigation of alternative splicing and mRNA expression patterns.

Main Results:

• A human CPEB protein (hCPEB) with sequence-specific RNA binding activity was cloned.
• Alternative splicing of hCPEB mRNA generates protein variants with conserved RNA-binding domains but different regulatory domains.
• hCPEB mRNA is expressed in the brain, heart, and immature oocytes.

Conclusions:

• Cytoplasmic polyadenylation is a likely mechanism for regulating human mRNA translation.
• hCPEB plays a role in controlling mRNA translation in both oocytes and somatic cells.
• This mechanism is conserved across species, highlighting its fundamental importance in gene regulation.