InterPro domain: IPR032691

This entry represent a domain found towards the N terminus in guanine nucleotide exchange factors involved Golgi transport, such as budding yeast protein Sec7 and protein Mon2.

Sec7 and its homologues are guanine nucleotide exchange factors (GEFs) involved in the secretory pathway [ 1 ]. The full-length Sec7 functions proximally in the secretory pathway as a protein binding scaffold for the coat protein complexes COPII-COPI [ 2 ]. The COPII-COPI-protein switch is necessary for maturation of the vesicular-tubular cluster, VTC, intermediate compartments for Golgi compartment biogenesis. This N-terminal domain however does not appear to be binding either of the COP or the ARF [ 3 ].

Mon2 is distantly related to the Arf1 guanine nucleotide exchange factors (GEFs), such as Sec7. However, it lacks the Sec7 domain that catalyses nucleotide exchange on Arf1. Instead, Mon2 acts as a scaffold to recruit the Golgi-localised pool of Dop1 [ 4 ].

1. The Sec7 guanine nucleotide exchange factor GBF1 regulates membrane recruitment of BIG1 and BIG2 guanine nucleotide exchange factors to the trans-Golgi network (TGN). J. Biol. Chem. 288, 11532-45
2. SEC7 encodes an unusual, high molecular weight protein required for membrane traffic from the yeast Golgi apparatus. J. Biol. Chem. 263, 11711-7
3. Sec7p directs the transitions required for yeast Golgi biogenesis. Traffic 1, 172-83
4. Mon2, a relative of large Arf exchange factors, recruits Dop1 to the Golgi apparatus. J. Biol. Chem. 281, 2273-80