More recently, in a chronic model of type 1 diabetes, Vadvalkar et al. [ 49] demonstrated that heart mitochondria may have substrate inflexibility as their respiration was reduced only with non-fatty acid substrates.
In contrast, a soft and readily deformable type-1 collagen substrate may have prevented substrate induced myofibroblast differentiation and allowed for more sensitive detection of the original changes in gene expression that more closely reflect the tissues of origin.
Therefore, it is likely that members of plant MMP family may have different substrates in plants and such substrate specificity may determine their biological functions.
Considering that the number of DUBs encoded in the genome is approximately one tenth the number of E3s, it is not surprising that a DUB may have multiple substrates and therefore act on multiple regulatory pathways in the cell.
This article explores the notion that Freudian constructs may have neurobiological substrates.
As well as collagen, both C-P3Hs and C-P4Hs may have additional substrates that contain collagen-like domains.
It is quite possible that laforin may have many substrates (such as other phosphatases), particularly since it is a dual specificity phosphatase that can hydrolyze phosphotyrosine as well as phosphoserine/threonine substrates in vitro (reviewed in 16).
Although Pofut1 may have additional substrates, Pofut1-null mice display Notch signaling defects that are similar to those associated with the loss of γ-secretase or Rbpj (Shi and Stanley, 2003; Okamura and Saga, 2008).
To define whether PINK1 may have additional substrates that are critical for mediating PINK1 downstream signalling in response to mitochondrial depolarization, we undertook a SILAC-based quantitative phosphoproteomic screen in Flp-In T-Rex HEK-293 cells stably expressing FLAG empty, wild-type or kinase-inactive PINK1 FLAG.
