This entry is specific to the first Longin domain of the HerMon (Hermansky-Pudlak syndrome and MON1-CCZ1) family, including protein sequences of FUZ, MON1 and HPS1 families [1,3,5]. The Mon1/Ccz1 complex (MC1) is the GDP/GTP exchange factor (GEF) for the Rab GTPase Ypt7/Rab7 during vesicular trafficking [2]. The Hps1/Hps4 complex (BLOC-3) is a Rab32 and Rab38 GEF and is required for biogenesis of melanosomes and platelet dense granules [3]. Inturned (INTU) and Fuzzy (FUZ) proteins interact as members of the ciliogenesis and planar polarity effector (CPLANE) complex that controls recruitment of intraflagellar transport machinery to the basal body of primary cilia [4,6].

1: Longin-like folds identified in CHiPS and DUF254 proteins: vesicle trafficking complexes conserved in eukaryotic evolution. Kinch LN, Grishin NV; Protein Sci. 2006;15:2669-2674. PMID:17075139

2: Architecture and mechanism of the late endosomal Rab7-like Ypt7 guanine nucleotide exchange factor complex Mon1-Ccz1. Kiontke S, Langemeyer L, Kuhlee A, Schuback S, Raunser S, Ungermann C, Kummel D; Nat Commun. 2017;8:14034. PMID:28051187

3: BLOC-3 mutated in Hermansky-Pudlak syndrome is a Rab32/38 guanine nucleotide exchange factor. Gerondopoulos A, Langemeyer L, Liang JR, Linford A, Barr FA; Curr Biol. 2012;22:2135-2139. PMID:23084991

4: The planar cell polarity effector Fuz is essential for targeted membrane trafficking, ciliogenesis and mouse embryonic development. Gray RS, Abitua PB, Wlodarczyk BJ, Szabo-Rogers HL, Blanchard O, Lee I, Weiss GS, Liu KJ, Marcotte EM, Wallingford JB, Finnell RH; Nat Cell Biol. 2009;11:1225-1232. PMID:19767740

5: Hexa-Longin domain scaffolds for inter-Rab signalling. Sanchez-Pulido L, Ponting CP; Bioinformatics. 2019 Sep 28. pii: 5575; [Epub ahead of print] PMID:31562761

6: The ciliopathy-associated CPLANE proteins direct basal body recruitment of intraflagellar transport machinery. Toriyama M, Lee C, Taylor SP, Duran I, Cohn DH, Bruel AL, Tabler JM, Drew K, Kelly MR, Kim S, Park TJ, Braun DA, Pierquin G, Biver A, Wagner K, Malfroot A, Panigrahi I, Franco B, Al-Lami HA, Yeung Y, Choi YJ, Duffourd Y, Faivre L, Riviere JB, Chen J, Liu KJ, Marcotte EM, Hildebrandt F, Thauvin-Robinet C, Krakow D, Jackson PK, Wallingford JB; Nat Genet. 2016;48:648-656. PMID:27158779