Serum-inducible gene expression in fibroblasts.

Area of Science:

• Cell biology
• Molecular biology
• Biochemistry

Background:

• Mammalian cell proliferation is controlled by external growth factors.
• Biochemical pathways triggered by growth factors modulate gene expression, leading to cell growth.
• Identifying genes that regulate cell growth is crucial for understanding cell proliferation.

Purpose of the Study:

• To identify, isolate, and characterize genes that modulate mammalian cell growth.
• To determine the functions of the protein products of these growth-regulated genes.
• To investigate the role of annexin II in the mitogenic process.

Main Methods:

• Sequence analysis to identify growth-regulated genes.
• Monitoring cytoplasmic transcript induction upon serum stimulation of quiescent cells.
• Analyzing changes in gene expression and protein localization in response to mitogenic stimulation.

Main Results:

• Several growth-regulated genes were identified, with induced cytoplasmic transcripts upon serum stimulation.
• Annexin II was identified as a growth-regulated gene and a major substrate of tyrosine kinases.
• Annexin II expression is growth-regulated, and its association with the membrane/cytoskeleton changes during mitogenic stimulation.

Conclusions:

• Growth-regulated genes, including annexin II, are functionally involved in the mitogenic process.
• Annexin II plays a role in regulating cell proliferation.
• Changes in annexin II's cellular localization correlate with cell growth stimulation.