The True Story of Yeti, the "Abominable" Heterochromatic Gene of Drosophila melanogaster

Abstract

The Drosophila Yeti gene (CG40218) was originally identified by recessive lethal mutation and subsequently mapped to the deep pericentromeric heterochromatin of chromosome 2. Functional studies have shown that Yeti encodes a 241 amino acid protein called YETI belonging to the evolutionarily conserved family of Bucentaur (BCNT) proteins and exhibiting a widespread distribution in animals and plants. Later studies have demonstrated that YETI protein: (i) is able to bind both subunits of the microtubule-based motor kinesin-I; (ii) is required for proper chromosome organization in both mitosis and meiosis divisions; and more recently (iii) is a new subunit of dTip60 chromatin remodeling complex. To date, other functions of YETI counterparts in chicken (CENtromere Protein 29, CENP-29), mouse (Cranio Protein 27, CP27), zebrafish and human (CranioFacial Development Protein 1, CFDP1) have been reported in literature, but the fully understanding of the multifaceted molecular function of this protein family remains still unclear. In this review we comprehensively highlight recent work and provide a more extensive hypothesis suggesting a broader range of YETI protein functions in different cellular processes.

Keywords: BCNT proteins; Drosophila melanogaster; YETI; chromatin remodeling complex; epigenetic regulation.

FIGURE 1

The YETI orthologous proteins. Blast alignments of YETI and its orthologous protein sequences from human (H. sapiens), mouse (M. musculus), bovine (B. taurus), chicken (G. gallus), Zebrafish (D. rerio) and yeast (S. cerevisiae). Note the high level of conservation (about 45% similarity) in the last 80 residues of the BCNT C-terminal domain (red line).

FIGURE 2

Subcellular YETI localization. (A) YETI::GFP fusion protein localizes in nuclei of salivary glands and (B) binds to polytene chromosomes. A nuclear immunolocalization of YETI protein is accordingly found in (C) spermatocytes, (D) elongated spermatids and (E) Drosophila S2 cells.

FIGURE 3

Interaction partners of YETI and its orthologs. YETI (D. melanogaster), hCFDP1 (H. sapiens) and SWR1 (S. cerevisiae) interacting proteins identified by using MIST (Molecular Interaction Search Tool). They refer only to physical interactions experimentally determined.