PROSITE documentation PDOC51469SUN domain profile
Sad1/UNC-84 (SUN)-domain proteins are inner nuclear membrane (INM) proteins that are part of bridging complexes linking cytoskeletal elements with the nucleoskeleton. Originaly identified based on an ~150-amino acid region of homology between the C terminus of the Schizosaccharomyces pombe Sad1 protein and the Caenorhabditis elegans UNC-84 protein, SUN proteins are present in the proteomes of most eucaryotes. In addition to the SUN domain, these proteins contain a transmembrane sequence and at least one coiled-coil domain and localize to the inner nuclear envelope. SUN proteins are anchored in the inner nuclear envelope by their transmembrane segment and oriented in the membrane such that the C-terminal SUN domain is located in the space between the inner and outer nuclear membrane. Here, the SUN domain can interact with the C-terminal tail of an outer nuclear envelope protein that binds to the cytoskeleton, including the centrosome [1,2,3].
Some proteins known to contain a SUN domain are listed below:
- Fission yeast spindle pole body-associated protein Sad1.
- Yeast spindle pole body assembly component MPS3, essential for nuclear division and fusion.
- Yeast uncharacterized protein SLP1.
- Caenorhabditis nuclear migration and anchoring protein UNC-84.
- Caenorhabditis SUN domain-containing protein 1 (sun-1), involved in centrosome attachment to the nucleus.
- Mammalian sperm-associated antigen 4 protein (SPAG4), may assist the organization and assembly of outer dense fibers (ODFs), a specific structure of the sperm tail.
- Mammalian sperm-associated antigen 4-like protein (SPAG4L).
- Mammalian SUN1.
- Mammalian SUN2.
- Mammalian SUN3.
The profile we developed covers the entire SUN domain.
Last update:November 2009 / First entry.
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PROSITE method (with tools and information) covered by this documentation:
| 1 | Authors | Mans B.J. Anantharaman V. Aravind L. Koonin E.V. |
| Title | Comparative genomics, evolution and origins of the nuclear envelope and nuclear pore complex. | |
| Source | Cell Cycle 3:1612-1637(2004). | |
| PubMed ID | 15611647 |
| 2 | Authors | Jaspersen S.L. Martin A.E. Glazko G. Giddings T.H. Jr. Morgan G. Mushegian A. Winey M. |
| Title | The Sad1-UNC-84 homology domain in Mps3 interacts with Mps2 to connect the spindle pole body with the nuclear envelope. | |
| Source | J. Cell Biol. 174:665-675(2006). | |
| PubMed ID | 16923827 | |
| DOI | 10.1083/jcb.200601062 |
| 3 | Authors | Graumann K. Runions J. Evans D.E. |
| Title | Characterization of SUN-domain proteins at the higher plant nuclear envelope. | |
| Source | Plant J. 0:0-0(2009). | |
| PubMed ID | 19807882 | |
| DOI | 10.1111/j.1365-313X.2009.04038.x |
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