Expression of sulfated gp300 and changes in glycosylation during pancreatic development.

Abstract

The pancreatic zymogen granule membrane protein gp300 is the major sulfated glycoprotein of the mouse acinar cell and has been proposed to be an important structural component of the zymogen granule membrane. A prediction of this proposed function is that gp300 expression should be coordinately regulated with the digestive enzymes and appearance of zymogen granules during differentiation of acinar cells in fetal development. By Western blots and immunolocalization with a polyclonal antiserum to gp300, we found that gp300 protein expression paralleled expression of amylase and the appearance of zymogen granules in differentiating acinar cells. Lectin blots were performed to assess the glycoconjugate composition of gp300 during development. Using the fucose binding lectin Ulex europaeus I, we found that gp300 acquires this carbohydrate only postnatally, temporally correlated with weaning. In addition, gp300 showed complex changes during postnatal development in reactivity with the galactose binding lectin peanut agglutinin (PNA) and the sialic acid binding lectin Maackia amuresis (MAA). Levels of reactivity of PNA and MAA were reciprocal, suggesting that sialylation of galactose (which can block peanut agglutinin binding) was not constant on gp300 during development.

Establishment and immunocharacterization of an immortalized pancreatic cell line derived from the H-2Kb-tsA58 transgenic mouse

“…However, it is conceivable that such structures cannot develop in rapidly dividing pancreatic acinar ceils. In support of this hypothesis is the observation that in the mouse pancreas zymogen granules appear at around Day 15.5 of embryonic development when cell proliferation has strongly declined (9). Therefore, it would be very interesting to determine in future work whether the biogenesis of zymogen granules can be induced in IMPAN cells when cultured under nonpermissive conditions.…”

Sulfated glycosaminoglycans in guinea pig basophils studied by means of cationic colloidal gold

“…Some authors have assumed that the tendency for the levels of acid mucosubstance to decline with maturation may be similar to the phenomenon observed in neutrophils, in which glycosaminoglycans link to lysosomal enzyme, resulting in masking of the reactive sites (Parmley et al 1983;Sakakibara and Eguchi 1985). Recent studies on pancreatic zymogen granules demonstrated that complex changes in carbohydrate composition occurred during development (De Lisle and Isom 1996). We assume this is also true in the development of basophils.…”

Altered posttranslational processing of glycoproteins in cerulein-induced pancreatitis

“…This compartment is believed to be the immature zymogen granule (condensing vacuole). Because sulfation of proteins occurs in the trans-Golgi network [17,24], [ 35 Because pro-Muclin and Muclin have complex glycosylation patterns, a variety of lectins can be used as probes for specific oligosaccharides as the protein is processed and matures [20,25]. A survey of several lectins was performed on acini just after the [ 35 S]met/cys pulse-labeling period and after a 2 h chase to determine which would be most revealing of processing of pro-Muclin and production of mature Muclin (not shown).…”