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3  structures 568  species 5  interactions 1235  sequences 27  architectures

Family: Cse1 (PF08506)

Summary: Cse1

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This is the Wikipedia entry entitled "CAS/CSE protein family". More...

CAS/CSE protein family Edit Wikipedia article

CAS/CSE protein, C-terminus
PDB 1z3h EBI.jpg
the exportin cse1 in its cargo-free, cytoplasmic state
Symbol CAS_CSE1
Pfam PF03378
InterPro IPR005043
PDB 1z3h EBI.jpg
the exportin cse1 in its cargo-free, cytoplasmic state
Symbol Cse1
Pfam PF08506
Pfam clan CL0020
InterPro IPR013713

In molecular biology, the CAS/CSE protein family is a family of proteins which includes mammalian cellular apoptosis susceptibility (CAS) proteins and yeast chromosome-segregation protein, CSE1.[1] CAS is involved in both cellular apoptosis and proliferation.[2][3] Apoptosis is inhibited in CAS-depleted cells, while the expression of CAS correlates to the degree of cellular proliferation. Like CSE1, it is essential for the mitotic checkpoint in the cell cycle (CAS depletion blocks the cell in the G2 phase), and has been shown to be associated with the microtubule network and the mitotic spindle,[3] as is the protein MEK, which is thought to regulate the intracellular localization (predominantly nuclear vs. predominantly cytosolic) of CAS. In the nucleus, CAS acts as a nuclear transport factor in the importin pathway.[4] The importin pathway mediates the nuclear transport of several proteins that are necessary for mitosis and further progression. CAS is therefore thought to affect the cell cycle through its effect on the nuclear transport of these proteins.[5] Since apoptosis also requires the nuclear import of several proteins (such as P53 and transcription factors), it has been suggested that CAS also enables apoptosis by facilitating the nuclear import of at least a subset of these essential proteins.[6]

The CAS/CSE family of proteins consist of two domains. An N-terminal Cse1 domain, which contains HEAT repeats, and a C-terminal domain.[7]


  1. ^ Brinkmann U, Brinkmann E, Gallo M, Pastan I (October 1995). "Cloning and characterization of a cellular apoptosis susceptibility gene, the human homologue to the yeast chromosome segregation gene CSE1". Proc. Natl. Acad. Sci. U.S.A. 92 (22): 10427–31. doi:10.1073/pnas.92.22.10427. PMC 40810. PMID 7479798. 
  2. ^ Brinkmann U, Brinkmann E, Gallo M, Scherf U, Pastan I (May 1996). "Role of CAS, a human homologue to the yeast chromosome segregation gene CSE1, in toxin and tumor necrosis factor mediated apoptosis". Biochemistry 35 (21): 6891–9. doi:10.1021/bi952829+. PMID 8639641. 
  3. ^ a b Scherf U, Pastan I, Willingham MC, Brinkmann U (April 1996). "The human CAS protein which is homologous to the CSE1 yeast chromosome segregation gene product is associated with microtubules and mitotic spindle". Proc. Natl. Acad. Sci. U.S.A. 93 (7): 2670–4. doi:10.1073/pnas.93.7.2670. PMC 39688. PMID 8610099. 
  4. ^ Kutay U, Bischoff FR, Kostka S, Kraft R, Gorlich D (September 1997). "Export of importin alpha from the nucleus is mediated by a specific nuclear transport factor". Cell 90 (6): 1061–71. doi:10.1016/S0092-8674(00)80372-4. PMID 9323134. 
  5. ^ Kutay U, Bischoff FR, Kostka S, Kraft R, Görlich D (September 1997). "Export of importin alpha from the nucleus is mediated by a specific nuclear transport factor". Cell 90 (6): 1061–71. doi:10.1016/S0092-8674(00)80372-4. PMID 9323134. 
  6. ^ Brinkmann U (March 1998). "CAS, the human homologue of the yeast chromosome-segregation gene CSE1, in proliferation, apoptosis, and cancer". Am. J. Hum. Genet. 62 (3): 509–13. doi:10.1086/301773. PMC 1376967. PMID 9497270. 
  7. ^ Cook, A.; Fernandez, E.; Lindner, D.; Ebert, J.; Schlenstedt, G.; Conti, E. (2005). "The Structure of the Nuclear Export Receptor Cse1 in Its Cytosolic State Reveals a Closed Conformation Incompatible with Cargo Binding". Molecular Cell 18 (3): 355–367. doi:10.1016/j.molcel.2005.03.021. PMID 15866177.  edit

This article incorporates text from the public domain Pfam and InterPro IPR005043

This article incorporates text from the public domain Pfam and InterPro IPR013713

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Cse1 Provide feedback

This domain is present in Cse1 nuclear export receptor proteins. Cse1 mediates the nuclear export of importin alpha. This domain contains HEAT repeats [1].

Literature references

  1. Cook A, Fernandez E, Lindner D, Ebert J, Schlenstedt G, Conti E; , Mol Cell 2005;18:355-367.: The structure of the nuclear export receptor Cse1 in its cytosolic state reveals a closed conformation incompatible with cargo binding. PUBMED:15866177 EPMC:15866177

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR013713

The exchange of macromolecules between the nucleus and cytoplasm takes place through nuclear pore complexes within the nuclear membrane. Active transport of large molecules through these pore complexes require carrier proteins, called karyopherins (importins and exportins), which shuttle between the two compartments.

This domain is found in exportin Cse1 (also known as importin-alpha re-exporter). Exportin Cse1 mediates nuclear transport of importin-alpha back into the cytosol, where importin-alpha functions as a transporter of proteins carrying nuclear localisation signals (NLS) from the cytoplasm into the nucleus [PUBMED:15602554, PUBMED:15866177, PUBMED:17170104]. This domain contains HEAT repeats.

More information about these proteins can be found at Protein of the Month: Importins [PUBMED:].

Gene Ontology

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Domain organisation

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Curation and family details

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Seed source: Pfam-B_9217 (release 17.0)
Previous IDs: none
Type: Domain
Author: Mistry J, Wood V
Number in seed: 15
Number in full: 1235
Average length of the domain: 292.80 aa
Average identity of full alignment: 23 %
Average coverage of the sequence by the domain: 31.67 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 80369284 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 20.3 20.3
Trusted cut-off 20.3 20.3
Noise cut-off 20.2 20.2
Model length: 370
Family (HMM) version: 6
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There are 5 interactions for this family. More...



For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Cse1 domain has been found. There are 3 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.

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