Activating Compound | Comment | Organism | Structure |
---|---|---|---|
Tbc1/cofactor C | acts as a GTPase-activating protein, GAP, in regulating GTPase Alp41/Arl2. Tbc1 and Alp41 directly interact. Tbc1 is the orthologue of cofactor C and is able to form a supercomplex with Alp1D and Alp21E. Temperature-sensitive mutants of tbc1 show loss of microtubules. If Tbc1 loses its GAP activity as in the tbc1-11 mutant, Alp41 will no longer be converted from its active, GTP-bound state to the inactive, GDP-bound state | Schizosaccharomyces pombe |
Cloned (Comment) | Organism |
---|---|
recombinant expression of His6-tagged Alp41 in Escherichia coli, coexpression with activator Tbc1. HAT-tagged Tbc1 coimmunoprecipitates with GFP-tagged Alp41 | Schizosaccharomyces pombe |
Protein Variants | Comment | Organism |
---|---|---|
additional information | overproduction of GTP or GDP form of Alp41 is toxic to the cell | Schizosaccharomyces pombe |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Schizosaccharomyces pombe |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
GTP + H2O | Schizosaccharomyces pombe | - |
GDP + phosphate | - |
? | |
GTP + H2O | Schizosaccharomyces pombe 972 | - |
GDP + phosphate | - |
? | |
additional information | Schizosaccharomyces pombe | Alp41 GTPase interacts with cofactor C, but with cofactor D, Alp1D, only when bound to GDP | ? | - |
? | |
additional information | Schizosaccharomyces pombe 972 | Alp41 GTPase interacts with cofactor C, but with cofactor D, Alp1D, only when bound to GDP | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Schizosaccharomyces pombe | Q09767 | gene alp41 | - |
Schizosaccharomyces pombe 972 | Q09767 | gene alp41 | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
GTP + H2O | - |
Schizosaccharomyces pombe | GDP + phosphate | - |
? | |
GTP + H2O | - |
Schizosaccharomyces pombe 972 | GDP + phosphate | - |
? | |
additional information | Alp41 GTPase interacts with cofactor C, but with cofactor D, Alp1D, only when bound to GDP | Schizosaccharomyces pombe | ? | - |
? | |
additional information | Alp41 GTPase interacts with cofactor C, but with cofactor D, Alp1D, only when bound to GDP | Schizosaccharomyces pombe 972 | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
Alp41 | - |
Schizosaccharomyces pombe |
Alp41/Arl2 | - |
Schizosaccharomyces pombe |
GTPase Alp41/Arl2 | - |
Schizosaccharomyces pombe |
small GTPase | - |
Schizosaccharomyces pombe |
General Information | Comment | Organism |
---|---|---|
evolution | Alp41/Arl2 is a highly conserved small GTPase | Schizosaccharomyces pombe |
malfunction | if Tbc1 loses its GAP activity as in the tbc1-11 mutant, Alp41 will no longer be converted from its active, GTP-bound state to the inactive, GDP-bound state. Overproduction of GTP or GDP form of Alp41 is toxic to the cell | Schizosaccharomyces pombe |
metabolism | the tubulin cofactor pathway consists of a specific set of chaperones that aid the folding of alpha- and beta-tubulin monomers into a functional heterodimer, with the introduction of cofactor C, GTP hydrolysis occurs, triggering the release of the newly folded alpha/beta-tubulin heterodimer for addition to the plus end of the microtubule, modeling of the final stages of the tubulin cofactor pathway that includes a dual role for both Tbc1 and Alp1D in opposing regulation of the microtubule. Alp41 GTPase interacts with cofactor D, Alp1D, only when bound to GDP | Schizosaccharomyces pombe |
physiological function | dual role of fission yeast Tbc1/cofactor C orchestrates microtubule homeostasis in tubulin folding and acts as a GTPase activating protein for GTPase Alp41/Arl2, Tbc1 and Alp41 directly interact, mutational analysis, overview. Tbc1 is the cofactor C involved in correct folding of alphabeta-tubulin heterodimers, critical for microtubule dynamics. The expression of GDP- or GTP-bound Alp41 shows a microtubule loss phenotype, continuous cycling between these forms seems important for its functions. Alp41 GTPase interacts with cofactor D, Alp1D, only when bound to GDP, GDP-bound Alp41 sequesters overproduced Alp1D from microtubules and rescues abnormal microtubule structures | Schizosaccharomyces pombe |