ABSTRACT
We herein report a case of recurrent infection caused by Verruconis gallopava, which is known to cause fatal phaeohyphomycosis. A 71-year-old man presented with a fever, and computed tomography revealed right chest wall thickening. Eleven years earlier, he had undergone autologous peripheral blood stem cell transplantation for a hematological malignancy. One year earlier, he had undergone excision of a solitary pulmonary nodule, from which had been detected V. gallopava. On this occasion, right chest wall surgery was performed to investigate the cause of the fever, which led to the diagnosis of recurrent infection. Even if a localized lesion is excised, additional antifungal therapy should be performed.
ABSTRACT
Microtubules (MTs) play critical roles in various cellular events, including cell migration. End-binding proteins (EBs) accumulate at the ends of growing MTs and regulate MT end dynamics by recruiting other plus end-tracking proteins (+TIPs). However, how EBs contribute to MT dynamics through +TIPs remains elusive. We focused on tau-tubulin kinase 2 (TTBK2) as an EB1/3-binding kinase and confirmed that TTBK2 acted as a +TIP. We identified MT-depolymerizing kinesin KIF2A as a novel substrate of TTBK2. TTBK2 phosphorylated KIF2A at S135 in intact cells in an EB1/3-dependent fashion and inactivated its MT-depolymerizing activity in vitro. TTBK2 depletion reduced MT lifetime (facilitated shrinkage and suppressed rescue) and impaired HeLa cell migration, and these phenotypes were partially restored by KIF2A co-depletion. Expression of nonphosphorylatable KIF2A, but not wild-type KIF2A, reduced MT lifetime and slowed down the cell migration. These findings indicate that TTBK2 with EB1/3 phosphorylates KIF2A and antagonizes KIF2A-induced depolymerization at MT plus ends for cell migration.
