Goodpasture Antigen-binding Protein (GPBP) Directs Myofibril Formation

Abstract

Background: GPBP-1 is a non-conventional kinase that regulates glomerular basement membrane collagen organization. Results: GPBP-1 targets GIP130, a new myosin-binding protein, and regulates myofibrillogenesis in cultured myoblasts. Conclusion: GPBP-1 regulates myofibril formation. Significance: GPBP-1 is a kinase for structural protein organization at both intracellular and extracellular compartments.

Embryo implantation triggers dynamic spatiotemporal expression of the basement membrane toolkit during uterine reprogramming

“…One isoform, GPBP-1, preferentially localizes extracellular matrix. The alternatively spliced isoform, GPBP-2 also known as CERT, is predominately cytosolic where it functions in intraorganelle lipid transport and vesicular transport to the plasma membrane [33,34,60]. First, to determine whether any GPBP was expressed, we quantified mRNA expression levels during early pregnancy and decidua development.…”

“…All sections were preincubated with 10% normal serum from goat or horse (Invitrogen, Grand Island, NY) for 1 hour at room temperature to avoid nonspecific binding of antibodies prior to applying primary antibodies. The following primary antibodies were used for antigen detections: rat anti-collagen IV NC1 (1:500 dilution, JK2, were from Y. Sado, Shigei Medical Research Institute, Okayama, Japan [95,96]), rabbit anti-laminin (1:50 dilution for tissues not treated with dissociation buffer and 1:500 dilution for those that were pre-treated with dissociation buffer, ab11575, Abcam, Cambridge, MA), rabbit anti-peroxidasin (1:250 dilution, were from G. Bhave, Vanderbilt University, Nashville, TN [27]), Alexa546 conjugated mouse anti-GPBP (1:50 dilution, mAb N26 to the N-terminal serine-rich domain conserved across all GPBP isoforms in several species [97], from Fibrostatin, SL, Valencia, Spain), and Alexa546 conjugated mouse anti-GPBP-1 (1:50 dilution, mAb e11-2 to the 26-amino acid residue of exon 11 not present in GPBP-2, also called CERT [60], from FIbrostatin, SL, Valencia, Spain). The secondary antibodies used for immunofluorescence detection were: Alexa555 goat anti-rat (1:200 dilution, ab150166, Abcam) and Alexa488 goat anti-rabbit (1:200 dilution, ab150081, Abcam).…”

Basement membrane ultrastructure and component localization data from uterine tissues during early mouse pregnancy

“…All antibodies were diluted in PBS/0.1% Tween with 5% goat serum. The following primary antibodies were applied to the sections: rat anti-collagen IV NC1 (1:500 dilution, JK2, were from Y. Sado, Shigei Medical Research Institute, Okayama, Japan [5], [6]), rabbit anti-laminin (1:50 dilution for tissues not treated with dissociation buffer and 1:500 dilution for those that were pre-treated with dissociation buffer, ab11575, Abcam, Cambridge, MA), rabbit anti-peroxidasin (1:250 dilution, were from G. Bhave, Vanderbilt University, Nashville, TN [7]), Alexa546 conjugated mouse anti-GPBP (1:50 dilution, mAb N26 to the N-terminal serine-rich domain conserved across all GPBP isoforms in several species [8], from Fibrostatin, SL, Valencia, Spain), and Alexa546 conjugated mouse anti-GPBP-1 (1:50 dilution, mAb e11-2 to the 26-amino acid residue of exon 11 not present in GPBP-2, also called CERT [9], from Fibrostatin, SL, Valencia, Spain). A previously described dissociation buffer was used on sections co-stained with collagen IV antibody (JK2) [1], [5] followed by several washes with PBS and PBS/0.2% Tween.…”

Unicellular ancestry and mechanisms of diversification of Goodpasture antigen–binding protein

“…Among BM proteins, GPBP was uniquely poised to also play a role in the appearance of BMs and the transition to multicellularity, owing to its multiple isoforms (23,26,27) with varied functions both inside (28,29) and outside of cells (22)(23)(24)30).…”

“…GPBP-1 mainly functions on the outside of cell as a kinase that phosphorylates collagen IV (23) and plays a role in BM assembly (22,24,30). GPBP-2 (also referred to as GPBP⌬26 or CERT, ceramide transporter protein) mainly functions inside of cells translocating ceramides (26,28). GPBP-3 is membrane-bound and functions to increase the secretion of GPBP-1 into the extracellular matrix (27).…”