Mitochondrial membrane permeability has received considerable attention recently because of its key role in apoptosis and
necrosis induced by physiological events such as
hypoxia. The manner in which mitochondria interact with other molecules to regulate mitochondrial permeability and cell destiny remains elusive. Previously we verified that
hypoxia-induced phosphorylation of
microtubule-associated protein 4 (
MAP4) could lead to microtubules (MTs) disruption. In this study, we established the hypoxic (1% O(2)) cell models of rat cardiomyocytes, H9c2 and HeLa cells to further test
MAP4 function. We demonstrated that increase in the pool of
MAP4 could promote the stabilization of MT networks by increasing the synthesis and polymerization of
tubulin in
hypoxia. Results showed
MAP4 overexpression could enhance cell viability and
ATP content under hypoxic conditions. Subsequently we employed a yeast two-hybrid system to tag a
protein interacting with mitochondria,
dynein light chain Tctex-type 1 (DYNLT1), by hVDAC1 bait. We confirmed that DYNLT1 had
protein-
protein interactions with
voltage-dependent anion channel 1 (VDAC1) using co-immunoprecipitation; and immunofluorescence technique showed that DYNLT1 was closely associated with MTs and VDAC1. Furthermore, DYNLT1 interactions with
MAP4 were explored using a knockdown technique. We thus propose two possible mechanisms triggered by
MAP4: (1) stabilization of MT networks, (2) DYNLT1 modulation, which is connected with VDAC1, and inhibition of
hypoxia-induced mitochondrial permeabilization.