摘要
The natural design for the generation and the fate of proteins in an organism could be as complicated as life itself. A protein is biosynthesized strictly according to the message carried by the mRNA transcribed from its gene. However, when, where, what and how much a gene is expressed are regulated precisely and dynamically at multiple levels, including at transcription, mRNA maturation, alternative splicing, and translation levels. A newly synthesized protein often needs to be further modified and sorted posttransla- tionally for its optimal confirmation and function. When a protein reaches its life span, the senescent protein is degraded by protein degradation machinery involving the ubiquitin-proteosome system and lysosomes. Protein homeostasis is essential for maintaining the normal mor- phology and function of the cell.
The natural design for the generation and the fate of proteins in an organism could be as complicated as life itself. A protein is biosynthesized strictly according to the message carried by the mRNA transcribed from its gene. However, when, where, what and how much a gene is expressed are regulated precisely and dynamically at multiple levels, including at transcription, mRNA maturation, alternative splicing, and translation levels. A newly synthesized protein often needs to be further modified and sorted posttransla- tionally for its optimal confirmation and function. When a protein reaches its life span, the senescent protein is degraded by protein degradation machinery involving the ubiquitin-proteosome system and lysosomes. Protein homeostasis is essential for maintaining the normal mor- phology and function of the cell.
