It is of note that targeting of Alp7C(LA6) to the kinetochore did not result in obvious TBZ resistance when wild-type Ndc80 was present in the cell [inndc80+nuf2-alp7C(LA6)]. We identified analp7mutant that had specific defects in binding to the Klp5Klp6PP1 complex but with normal localisation to the microtubule and kinetochore. Consistent with our proposition, this mutant shows delayed anaphase onset and decelerated chromosome movement during anaphase A. We propose that the recruitment of kinesin-8PP1 to the kinetochore through Alp7/TACC interaction plays a crucial role in regulation of timely mitotic progression and chromosome movement during anaphase A. KEY WORDS: Alp7/TACC, Kinesin-8, Protein phosphatase I, MLL3 Ndc80, Anaphase A, Spindle assembly checkpoint/fission yeast == INTRO == During mitosis, the microtubules grow from the opposite spindle poles and hole to the kinetochore, a multi-protein structure found on the centromeric DNA (Cheeseman and Desai, 2008; Spautin-1 Takeuchi and Fukagawa, 2012). The kinetochoremicrotubule attachment is monitored by a surveillance mechanism known as the spindle assembly checkpoint (SAC) (Musacchio and Salmon, 2007; Lara-Gonzalez et al., 2012). When errors in kinetochoremicrotubule attachment are detected, the SAC, in which Mad2 represents a central protein, is activated to allow time for correction of faulty attachment through inhibiting the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase (He et al., 1997; Hwang et al., 1998; Kim et al., 1998). Subsequently, upon establishment of proper kinetochoremicrotubule attachment, the SAC must be silenced (or deactivated) to allow anaphase onset and segregation of sister chromatids into two daughter cells (Lesage et al., 2011). The type I protein phosphatase (PP1) has been shown to play a crucial role in checkpoint silencing (Pinsky et al., 2009; Vanoosthuyse and Hardwick, 2009). However , how PP1 imposes SAC silencing coincident with the establishment of end-on attachment remains unexplored. In the past decades, several studies possess revealed the importance of the outer kinetochore Spautin-1 complex component Ndc80/Hec1 in regulating microtubule attachment. The N-terminal region of Ndc80 interacts directly with all the spindle microtubules (Wei et al., 2007; Ciferri et al., 2008). In addition , the Ndc80 Spautin-1 internal loop helps to recruit diverse regulatory proteins to ensure accurate chromosome segregation (Nilsson, 2012; Tang and Toda, 2013; Tang and Toda, 2014). In human being cells, the licensing element Cdt1 binds to the Ndc80 loop to alter the Ndc80 conformation to an extended type (Varma et al., 2012), whereas localisation of the spindle and kinetochore-associated (Ska) complex to the kinetochore is important intended for the establishment of end-on attachment (Zhang et al., 2012). In budding yeast, the Dam1 complex localises to the kinetochore through the Ndc80 internal loop and plays crucial roles in the conversion of lateral to end-on attachment (Maure et al., 2011). In fission yeast, the Ndc80 internal loop recruits both the Dis1/TOG and the Alp7/TACCAlp14/TOG complex (Hsu and Toda, 2011; Tang et al., 2013). Members from the conserved XMAP215/ch-TOG (colonic hepatic tumour overexpressed gene) microtubule-associated protein family members (Garcia et al., 2001; Nakaseko et al., 2001; Ohkura et al., 2001; Kinoshita et al., 2002) are known to be plus-end tracking proteins (+TIPs) with microtubule polymerase activities (Brouhard et al., 2008; Al-Bassam and Chang, 2011; Widlund et al., 2011; Al-Bassam et al., 2012; Podolski et al., 2014). Both Dis1 and Alp14 belong to this family and discuss essential functions (Nabeshima et al., 1995; Garcia et al., 2001; Nakaseko et al., 2001; Garcia et al., 2002a). Despite this, there are several differences between Dis1 and Alp14. First, Alp14, but not Dis1, forms a complex with Alp7 protein (Sato et al., 2004). Second, in early mitosis, Dis1 localises to the kinetochore (Nakaseko et al., 2001; Hsu and Toda, 2011), whereas Alp14 is initially targeted to the spindle pole body (SPB) through Alp7, then localises to spindle microtubules and finally reaches the kinetochores upon attachment (Sato et al., 2004; Sato and Toda, 2007; Kakui et al., 2013; Okada et al., 2014; Tang et al., 2013; Tang et al., 2014; Zheng et al., 2014). We have previously shown.