Search results
Results from the WOW.Com Content Network
Using cycling extracts, they observed that the activation threshold for Δcyclin B is between 32 and 42 nM whereas the inactivation threshold is between 16 and 24 nM Δcyclin B. Therefore, these experiments confirmed the bistability of this system and the importance of hysteresis in this cell cycle transition.
The formation of the eukaryotic initiation complex. In cancerous cells, initiation factors assist in cellular transformation and development of tumors. The survival and growth of cancer is directly related to the modification of initiation factors and is used as a target for pharmaceuticals. Cells need increased energy when cancerous and derive ...
In the absence of coherent gene expression, cells take longer to exit G1 and a significant fraction even arrest before S phase, highlighting the importance of positive feedback in sharpening the G1/S switch. The G1/S cell cycle checkpoint controls the passage of eukaryotic cells from the first gap phase, G1, into the DNA synthesis phase, S.
Eukaryotic initiation factors (eIFs) are proteins or protein complexes involved in the initiation phase of eukaryotic translation. These proteins help stabilize the formation of ribosomal preinitiation complexes around the start codon and are an important input for post-transcription gene regulation .
Chromosome replication proceeds in three major stages: initiation, elongation and termination. The initiation stage starts with the ordered assembly of "initiator" proteins at the origin region of the chromosome, called oriC. These assembly stages are regulated to ensure that chromosome replication occurs only once in each cell cycle.
The eukaryotic cell cycle consists of four distinct phases: G 1 phase, S phase (synthesis), G 2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm and cell membrane divides forming two daughter cells.
During each cell cycle, it is important that the genome be completely replicated once and only once. Formation of the pre-replication complex during late M and early G1 phase is required for genome replication, but after the genome has been replicated the pre-RC must not form again until the next cell cycle.
The IF2 initiation factor is a crucial component in the process of protein synthesis. The largest among the three indispensable translation initiation factors is IF-2, which possesses a molecular mass of 97 kDa. [17] [18] The protein has many domains, including an N-terminal domain, a GTPase domain, a linker region, C1, C2, and C-terminal domains.