This is entry represents the cell cycle regulator Mat89b (also known as protein asunder), which plays an evolutionarily conserved role as a crucial regulator of both cell cycle and development [1, 2]. It is a component of INT (Integrator) complex, being involved in the 3'-end processing of the U7 snRNA, and also the spliceosomal snRNAs U1 and U5 [3]. Mat89Bb is also required for the correct dynein-dynactin perinuclear localization [4]. Mat89Bb is a PNG kinase substrate, that is essential for S-M cycles of early Drosophila embryogenesis, Xenopus embryonic cell cycles and morphogenesis, and cell division in cultured mammalian cells.

1: Drosophila genome-scale screen for PAN GU kinase substrates identifies Mat89Bb as a cell cycle regulator. Lee LA, Lee E, Anderson MA, Vardy L, Tahinci E, Ali SM, Kashevsky H, Benasutti M, Kirschner MW, Orr-Weaver TL; Dev Cell. 2005;8:435-442. PMID:15737938

2: Nuclear-localized Asunder regulates cytoplasmic dynein localization via its role in the integrator complex. Jodoin JN, Sitaram P, Albrecht TR, May SB, Shboul M, Lee E, Reversade B, Wagner EJ, Lee LA; Mol Biol Cell. 2013;24:2954-2965. PMID:23904267

3: An RNAi screen identifies additional members of the Drosophila Integrator complex and a requirement for cyclin C/Cdk8 in snRNA 3'-end formation. Chen J, Ezzeddine N, Waltenspiel B, Albrecht TR, Warren WD, Marzluff WF, Wagner EJ; RNA. 2012;18:2148-2156. PMID:23097424

4: Asunder is a critical regulator of dynein-dynactin localization during Drosophila spermatogenesis. Anderson MA, Jodoin JN, Lee E, Hales KG, Hays TS, Lee LA; Mol Biol Cell. 2009;20:2709-2721. PMID:19357193