Glomerular basement membrane: evidence for collagenous domain of the alpha 3 and alpha 4 chains of collagen IV.
Abstract A collagenous component(s) of Mr = 60K was extracted from glomerular basement membrane with urea and was purified. Upon digestion, it yielded a collagenase-resistant fragment(s) of Mr = 23.5K. Both component and fragment showed immunochemical identity with the noncollagenous domains of the new α3 & α4 chains of collagen IV. The component is characterized by a collagenous domain of about 280 residues and a noncollagenous domain of about 250 residues. These findings further establish these new chains as distinct entities of collagen IV.
Structures of collagen IV globular domains: insight into associated pathologies, folding and network assembly
15 páginas, 6 figuras, 1 tabla.
Goodpasture Antigen-binding Protein (GPBP) Directs Myofibril Formation
Goodpasture antigen-binding protein-1 (GPBP-1) is an exportable non-conventional Ser/Thr kinase that regulates glomerular basement membrane collagen organization. Here we provide evidence that GPBP-1 accumulates in the cytoplasm of differentiating mouse myoblasts prior to myosin synthesis. Myoblasts deficient in GPBP-1 display defective myofibril formation, whereas myofibrils assemble with enhanced efficiency in those overexpressing GPBP-1. We also show that GPBP-1 targets the previously unidentified GIP130 (GPBP-interacting protein of 130 kDa), which binds to myosin and promotes its myofibrillar assembly. This report reveals that GPBP-1 directs myofibril formation, an observation that expa…
Structures of collagen IV globular domains: insight into associated pathologies, folding and network assembly. Corrigendum
The article by Casino et al. [IUCrJ (2018). 5, 765–779] is corrected.
Unicellular ancestry and mechanisms of diversification of Goodpasture antigen-binding protein.
The emergence of the basement membrane (BM), a specialized form of extracellular matrix, was essential in the unicellular transition to multicellularity. However, the mechanism is unknown. Goodpasture antigen–binding protein (GPBP), a BM protein, was uniquely poised to play diverse roles in this transition owing to its multiple isoforms (GPBP-1, -2, and -3) with varied intracellular and extracellular functions (ceramide trafficker and protein kinase). We sought to determine the evolutionary origin of GPBP isoforms. Our findings reveal the presence of GPBP in unicellular protists, with GPBP-2 as the most ancient isoform. In vertebrates, GPBP-1 assumed extracellular function that is further e…