Volume 7 Issue 2, February 2005

Bcl-2 has previously been characterized as an anti-apoptotic protein. However, it has now been linked to DNA mismatch repair (MMR). By retaining E2F-1 in a transcriptionally inactive state, through the induction of hypophosphorylated retinoblastoma protein, Bcl-2 hinders the expression of a key component of mismatch repair, MSH2. This study could therefore help to explain the mutagenicity that is associated with Bcl-2.

How cells maintain the balance between membrane fission and fusion is not known. Recent results show that Vps1p, a yeast dynamin-like protein, is involved in both processes at the vacuole, indicating that these two antagonistic reactions might be connected after all.

Mechanosensitive channels are essential for effective cellular function, but elucidation of their molecular identity and mechanisms of activation has proven difficult. Two recent studies now implicate members of the transient receptor potential (TRP) family as components of the mechanosensitive channels in vertebrate hair cells (TRPA1) and stretch-activated channels (TRPC1) in several different vertebrate cell types.

The mammalian Forkhead Box M1 (FoxM1) protein, known for its function as a transcriptional regulator of G1/S progression, is also crucial for the G2/M transition. Some of its target genes are cyclin B, Cdc25B phosphatase, Aurora B kinase and Polo-like kinase. Furthermore, identification of the nuclear protein CENP-F as a transcriptional target of FoxM1 reveals how it can also regulate the spindle assembly checkpoint, thereby ensuring proper chromosome stability and segregation during mitosis.