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Dual localization: proteins in extracellular and intracellular compartments
1Department of Chemistry and Biochemistry, Calvin College, Grand Rapids, MI 49546, USA.
Acta Histochemica
|January 30, 2007
Summary
This catalog details proteins found both inside and outside cells, including those in the nucleus and extracellular space. Understanding these dual-localized proteins offers new insights into cellular transport and function.
Area of Science:
- Cell Biology
- Molecular Biology
- Proteomics
Background:
- Many proteins function in multiple cellular locations, a phenomenon termed dual localization.
- Proteins can reside in extracellular compartments (cell surface, medium) and intracellular compartments (cytosol, nucleus).
- Understanding protein trafficking signals is crucial for deciphering their localization and function.
Purpose of the Study:
- To create a comprehensive catalog of proteins exhibiting dual localization.
- To categorize these proteins based on the presence or absence of specific trafficking signals (signal sequence, nuclear localization signal).
- To highlight the physiological significance and novel insights gained from studying dual-localized proteins.
Main Methods:
- Literature review and data compilation to identify proteins with documented dual localization.
- Classification of proteins based on their signal sequences (for extracellular/cell surface targeting) and nuclear localization signals (for nuclear import).
- Categorization into four groups: signal sequence only, both signals, nuclear localization signal only, or neither signal.
Main Results:
- A catalog of dual-localized proteins was compiled and organized by trafficking signal profiles.
- Identified proteins with signal sequences but no nuclear localization signals.
- Identified proteins with both signal sequences and nuclear localization signals.
- Identified proteins with nuclear localization signals but no signal sequences.
- Identified proteins with neither signal sequence nor nuclear localization signal.
Conclusions:
- Dual localization is a significant feature of many proteins, with a notable subset found in both the nucleus and extracellular space.
- Experimental abrogation of targeting signals provides novel insights into protein function, such as the nuclear requirement for mitogenic activity.
- Integral membrane receptors can translocate to the nucleus, exhibiting transcription activation activity.
- This catalog serves as a foundation for further research into the mechanisms and physiological importance of dual protein localization.
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