TCTEX1D4, a novel protein phosphatase 1 interactor: connecting the phosphatase to the microtubule network

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Korrodi Gregorio, L (Author) Other; Vieira, SI (Author) Other; Esteves, SLC (Author) Other; Silva, JV (Author) Other; Freitas, MJ (Author) Other; Brauns, AK (Author) Other; Luers, G (Author) Other; Abrantes, J (Author) Other; Esteves, PJ (Author) FCUP; da Cruz e Silva, OABDE (Author) Other; Fardilha, M (Author) Other; da Cruz e Silva, EFDE (Author) Other

Journal

Title: Biology Open

Vol. 2

Pages: 453-465

Publisher: The Company of Biologists Ltd.

Indexing

ISI Web of Knowledge - 14 Citations

Scopus - 0 Citations

Other information

Authenticus ID: P-00G-9QF

DOI: 10.1242/bio.20131065

Abstract (EN): Reversible phosphorylation plays an important role as a mechanism of intracellular control in eukaryotes. PPP1, a major eukaryotic Ser/Thr-protein phosphatase, acquires its specificity by interacting with different protein regulators, also known as PPP1 interacting proteins (PIPs). In the present work we characterized a physiologically relevant PIP in testis. Using a yeast two-hybrid screen with a human testis cDNA library, we identified a novel PIP of PPP1CC2 isoform, the T-complex testis expressed protein 1 domain containing 4 (TCTEX1D4) that has recently been described as a Tctex1 dynein light chain family member. The overlay assays confirm that TCTEX1D4 interacts with the different spliced isoforms of PPP1CC. Also, the binding domain occurs in the N-terminus, where a consensus PPP1 binding motif (PPP1BM) RVSF is present. The distribution of TCTEX1D4 in testis suggests its involvement in distinct functions, such as TGF beta signaling at the blood-testis barrier and acrosome cap formation. Immunofluorescence in human ejaculated sperm shows that TCTEX1D4 is present in the flagellum and in the acrosome region of the head. Moreover, TCTEX1D4 and PPP1 co-localize in the microtubule organizing center (MTOC) and microtubules in cell cultures. Importantly, the TCTEX1D4 PPP1BM seems to be relevant for complex formation, for PPP1 retention in the MTOC and movement along microtubules. These novel results open new avenues to possible roles of this dynein, together with PPP1. In essence TCTEX1D4/PPP1C complex appears to be involved in microtubule dynamics, sperm motility, acrosome reaction and in the regulation of the blood-testis barrier. (C) 2013. Published by The Company of Biologists Ltd.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13