NUCLEOCYTOPLASMIC TRANSPORT OF PROTEINS AND CONTROL OF CELLULAR FUNCTION

Nucleocytoplasmic transport of proteins occurs through pores embedded in the nuclear envelope. Recent studies have defined the cytoplasmic f actors required for signal-mediated import of nuclear proteins. Consid erable progress has been made in understanding the mechanism of nuclea r export of proteins by the identification of specific signal sequence s needed for export. Regulatory molecules have been shown to adopt nov el mechanisms To control their entry into the nucleus and thereby regu late their functions.