PubMed Health⌕ Search

Biomedical subjects

James R Goldenring

Publications and source records attributed to James R Goldenring.

42 records · Page 3Linked to original sources
PubMed2002

AKAP350 at the Golgi apparatus. II. Association of AKAP350 with a novel chloride intracellular channel (CLIC) family member.

AKAP350 can scaffold a number of protein kinases and phosphatases at the centrosome and the Golgi apparatus. We performed a yeast two-hybrid screen of a rabbit parietal cell library with a 3.2-kb segment of AKAP350 (nucleotides 3611-6813). This screen yielded a full-length clone of rabbit chloride intracellular channel 1 (CLIC1). CLIC1 belongs to a family of proteins, all of which contain a high degree of homology in their carboxyl termini. All CLIC family members were able to bind a 133-amino acid domain within AKAP350 through the last 120 amino acids in the conserved CLIC carboxyl termini. Antibodies developed against a bovine CLIC, p64, immunoprecipitated AKAP350 from HCA-7 colonic adenocarcinoma cell extracts. Antibodies against CLIC proteins recognized at least five CLIC species including a novel 46-kDa CLIC protein. We isolated the human homologue of bovine p64, CLIC5B, from HCA-7 cell cDNA. A splice variant of CLIC5, the predicted molecular mass of CLIC5B corresponds to the molecular mass of the 46-kDa CLIC immunoreactive protein in HCA-7 cells. Antibodies against CLIC5B colocalized with AKAP350 at the Golgi apparatus with minor staining of the centrosomes. AKAP350 and CLIC5B association with Golgi elements was lost following brefeldin A treatment. Furthermore, GFP-CLIC5B-(178-410) targeted to the Golgi apparatus in HCA-7 cells. The results suggest that AKAP350 associates with CLIC proteins and specifically that CLIC5B interacts with AKAP350 at the Golgi apparatus in HCA-7 cells.

A Kinase Anchor Proteins↗
PubMed2002

AKAP350 at the Golgi apparatus. I. Identification of a distinct Golgi apparatus targeting motif in AKAP350.

The protein kinase A-anchoring proteins (AKAPs) are defined by their ability to scaffold protein kinase A to specific subcellular compartments. Each of the AKAP family members utilizes unique targeting domains specific for a particular subcellular compartment. AKAP350 is a multiply spliced AKAP family member localized to the centrosome and the Golgi apparatus. Three splicing events in the carboxyl terminus of AKAP350 generate the AKAP350A, AKAP350B, and AKAP350C proteins. A monoclonal antibody recognizing all three splice variants as well as a polyclonal antibody specific for AKAP350A demonstrated both centrosomal and Golgi apparatus staining in paraformaldehyde-fixed HCA-7 cells. Golgi apparatus-associated AKAP350A staining was dispersed following brefeldin A treatment. Using GFP chimeric constructs of the carboxyl-terminal regions of AKAP350A, a Golgi apparatus targeting domain was identified between amino acids 3259 and 3307 of AKAP350A. This domain was functionally distinguishable from the recently described centrosomal targeting domain (PACT domain, amino acids 3308-3324) located adjacent to the Golgi targeting domain. These data definitively establish the specific association of AKAP350A with the Golgi apparatus in HCA-7 cells.

Amino Acid Motifs↗
PubMed2002

Transforming acidic coiled-coil-containing protein 4 interacts with centrosomal AKAP350 and the mitotic spindle apparatus.

AKAP350 is a multiply spliced family of 350-450-kDa protein kinase A-anchoring proteins localized to the centrosomes and the Golgi apparatus. Using AKAP350A as bait in a yeast two-hybrid screen of a rabbit parietal cell library, we have identified a novel AKAP350-interacting protein, transforming acidic coiled-coil-containing protein 4 (TACC4). Two-hybrid binary assays demonstrate interaction of both TACC3 and TACC4 with AKAP350A and AKAP350B. Antibodies raised to a TACC4-specific peptide sequence colocalize TACC4 with AKAP350 at the centrosome in interphase Jurkat cells. Mitotic cell staining reveals translocation of TACC4 from the centrosome to the spindle apparatus with the majority of TACC4 at the spindle poles. Truncated TACC4 proteins lacking the AKAP350 minimal binding domain found in the carboxyl coiled-coil region of TACC4 could no longer target to the centrosome. Amino-truncated TACC4 proteins could no longer target to the spindle apparatus. Further, overexpression of TACC4 fusion proteins that retained spindle localization in mitotic cells resulted in an increased proportion of cells present in prometaphase. We propose that AKAP350 is responsible for sequestration of TACC4 to the centrosome in interphase, whereas a separate TACC4 domain results in functional localization of TACC4 to the spindle apparatus in mitotic cells.

A Kinase Anchor Proteins↗
PubMed2002

Identification of spasmolytic polypeptide expressing metaplasia (SPEM) in remnant gastric cancer and surveillance postgastrectomy biopsies.

Following gastrectomy, the remnant oxyntic mucosa is at increased risk of developing adenocarcinoma. Alkaline pancreaticoduodenal reflux, carcinogen production from intragastric bacterial overgrowth, denervation, and devascularization have been implicated in this malignant transformation. Recent reports have described a novel spasmolytic polypeptide (SP) expressing metaplastic lineage designated as SPEM. This lineage has been identified in the mucosa surrounding gastric adenocarcinomas, and SP staining has been observed in the cells of surface dysplasia and invasive malignancy. In this study we describe 19 cases of remnant gastric adenocarcinoma from Japan. In addition, we studied surveillance biopsies in 90 patients who underwent antrectomy for carcinoma. SPEM was identified in the mucosa surrounding 88% of the remnant cancers, as well as in 61% of the surveillance biopsies. In the malignant resections, 67% of the surface dysplasia displayed SP positive cells, and 25% revealed SP immunostaining within invasive malignant cells. These findings implicate SPEM as a potential precursor lesion of gastric adenocarcinoma.

Adenocarcinoma↗
PubMed2002

Association of spasmolytic polypeptide-expressing metaplasia with carcinogen administration and oxyntic atrophy in rats.

Spasmolytic polypeptide (TFF2)-expressing metaplasia (SPEM) is a gastric metaplastic lineage associated with the development of intestinal-type gastric adenocarcinoma. To study the etiology of this potential neoplastic precursor metaplasia, we used surgical rat models of remnant gastric adenocarcinoma studied with and without exposure to nitroso carcinogen. Animals with truncal vagotomy without duodenogastric reflux procedures demonstrated normal mucous neck cell spasmolytic polypeptide (SP) immunostaining. In these animals, anti-proliferating cell nuclear antigen (PCNA)-labeled nuclei were found in the normal midgland progenitor zone. Rats that received anatomic alterations that augmented the degree of duodenogastric reflux, however, revealed expansion of basally placed SP immunoreactive cells with early phenotypic changes of SPEM. Seventy percent of animals with antrectomy and carcinogen (with or without vagotomy) developed SPEM at the base of the gastric mucosa. In association with the appearance of this metaplastic lineage, a distinct second zone of PCNA-labeled nuclei developed in the deepest portion of the mucosa. Of interest, three animals demonstrating these changes developed intestinal-type gastric adenocarcinoma. Finally, we studied the immunostaining pattern of intrinsic factor, normally a chief cell marker in rat fundic mucosa. In animals with SPEM, we observed coexpression of SP and intrinsic factor in SPEM cells at the base of the mucosa. These findings support our hypothesis that SPEM develops from a second progenitor cell population, reflecting either the unmasking of a cryptic zone or transdifferentiation of chief cells.

Animals↗