High impact information on SKI8

• Interaction of Ski8 with Spo11 is essential for DSB formation and Ski8 relocalization [1].
• Ski8 works with Spo11 to recruit other DSB proteins to meiotic chromosomes, implicating Ski8 as a scaffold protein mediating assembly of a multiprotein complex essential for DSB formation [1].
• However, obligate partners of Ski8 in RNA metabolism are dispensable for recombination and Ski8 relocalizes to the nucleus and associates with chromosomes specifically during meiosis [1].
• An alternative 3'-to-5' decay pathway also follows the deadenylation and requires two multi-complexes: the exosome containing various 3'-exonucleases and the Ski complex consisting of the RNA helicase Ski2p, Ski3p and Ski8p [2].
• Previous results have shown that this degradation requires components of the exosome and the Ski2p, Ski3p, and Ski8p proteins, which were originally identified due to their superkiller phenotype [3].

Biological context of SKI8

• A region of chromosome VII adjacent to SKI8 has a 453 amino acid open reading frame whose sequence has significant similarity to that of HCS26, a G1 cyclin [4].
• A yeast antiviral protein, SKI8, shares a repeated amino acid sequence pattern with beta-subunits of G proteins and several other proteins [5].
• Our DNA sequence of SKI8 shows that it encodes a 397 amino acid protein containing two copies of a 31 amino acid repeat pattern first identified in mammalian beta-transducin and Cdc4p of yeast [5].
• The SKI8 gene was disrupted and found to be nonessential for cell growth in the absence of M double-stranded RNA (dsRNA) [6].
• REC103/SK18 is transcribed in mitotic cells and is induced approximately 15-fold in meiosis [7].

Physical interactions of SKI8

• Ski7p interacts with the Ski complex via its interaction with Ski8p and Ski3p [8].

Other interactions of SKI8

• The yeast antiviral proteins Ski2p, Ski3p, and Ski8p exist as a complex in vivo [9].
• REC103 maps to chromosome VII between ADE5 and RAD54 [7].
• Molecular and genetic analysis of REC103, an early meiotic recombination gene in yeast [7].
• Antiviral protein Ski8 is a direct partner of Spo11 in meiotic DNA break formation, independent of its cytoplasmic role in RNA metabolism [1].

Analytical, diagnostic and therapeutic context of SKI8

• Ski8p was thought to contain five WD repeats on the basis of primary sequence analysis implying a five-bladed propeller [10].

References