Targeting and function in mRNA export of nuclear pore complex protein Nup153

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• Nuclear pore complexes (NPCs) regulate nucleocytoplasmic transport.
• Nup153 is a key component of the NPC basket structure.
• Its role in RNA export is not fully understood.

Purpose of the Study:

• To investigate the function of Nup153 in nuclear export.
• To identify the domains of Nup153 responsible for RNA trafficking.
• To elucidate the mechanism of Nup153's role in mRNA export.

Main Methods:

• Expression of full-length and truncated Nup153 constructs in BHK cells.
• Analysis of poly (A)+ RNA distribution and nuclear protein import.
• Microscopy to observe NPC structure and intranuclear arrays.

Main Results:

• Nup153 overexpression causes nuclear poly (A)+ RNA accumulation, inhibiting RNA export.
• This defect is specifically linked to the COOH-terminal domain of Nup153.
• Nuclear protein import remains unaffected, indicating a specific RNA export defect.
• Intranuclear membrane arrays formed by some constructs did not correlate with RNA export defects.

Conclusions:

• The COOH-terminal domain of Nup153, containing XFXFG repeats, is crucial for mRNA export.
• Nup153's COOH-terminal region likely acts as a docking site for exiting mRNA.
• Nup153 plays a specific role in regulating mRNA export from the nucleus.