Cytoplasmic polyadenylation by TENT5A is required for proper bone formation

Area of Science:

• Biochemistry
• Molecular Biology
• Skeletal Biology

Background:

• Osteoblasts are crucial for bone formation, secreting type I collagen for mineralization.
• Mutations in TENT5A are linked to osteogenesis imperfecta, a congenital bone disease.

Purpose of the Study:

• To investigate the role of TENT5A in osteoblast differentiation and bone mineralization.
• To elucidate the mechanism by which TENT5A regulates collagen production.

Main Methods:

• Direct RNA sequencing to analyze TENT5A's targets.
• Generation and analysis of Tent5a knockout mouse models.

Main Results:

• TENT5A expression increases during osteoblast differentiation.
• TENT5A polyadenylates mRNAs for collagen type I (Col1α1, Col1α2) and other secreted proteins, enhancing their expression.
• Tent5a knockout mice exhibit bone fragility and hypomineralization due to collagen defects.

Conclusions:

• TENT5A is a cytoplasmic poly(A) polymerase critical for bone mineralization.
• TENT5A regulates collagen production post-transcriptionally, impacting skeletal development.
• TENT5A, potentially with TENT5C, orchestrates a wave of mRNA polyadenylation during bone formation.