Disease relevance of AMY1A

• The nucleotide sequence homologies of cDNAs between this carcinoid amylase and amy1, amy2 are 97.5% and 98.2%, respectively [1].
• The AMY1 gene (salivary type) was exclusively and highly expressed in the salivary glands and the amylase-producing lung adenocarcinomas [2].
• The results indicated that the parotid gland and hepatoma (also liver) clearly expressed AMY 1 and AMY 2B genes, respectively [3].
• A variety of conditions other than pancreatitis were associated with hyperamylasemia, and some patients who were thought on clinical grounds to have pancreatitis had raised levels of AMY1 (salivary) amylase [4].
• Vitreoscilla hemoglobin (VHb) gene was expressed in S. occidentalis under the control of the native alpha-amylase (AMY1) promoter [5].

High impact information on AMY1A

• These results indicate the possible location of a CMT1 gene between the AMY1 and AT3 loci at p21 and q23, respectively, on chromosome 1 and support the theory that there is at least one other CMT1 gene [6].
• We studied the distribution of alpha-amylase mRNA in normal dog tissues by northern blotting (NB) and reverse transcription-polymerase chain reaction (RT-PCR) with human pancreatic (AMY2) and salivary (AMY1) alpha-amylase cDNA-specific primers [7].
• AMY1 transcripts were detected in parotid, but not in pancreas or liver [8].
• Conversely, the salivary (Amy1) locus is expressed as early as 18 weeks of gestation and remains relatively constant with but a small increase in salivary amylase (units/ml) activity during early development, as the total amylase activity approaches adult values [9].
• We show here that, using anti-AMY-1 antibodies we raised, AMY-1 localizes to the trans-Golgi network (TGN) and the nucleus [10].

Biological context of AMY1A

• These findings can be explained by unequal homologous crossovers between AMY2A and AMY1A, resulting in haplotypes with one gene less or one gene more than the haplotypes described thus far [11].
• Nucleotide sequence analysis showed that the amylase expressed in this carcinoid tumor has 13 and 6 amino acid substitutions when compared with salivary amylase (Amy1) and pancreatic amylase (Amy2), respectively [1].
• It consists of ten major exons whose sequences are highly homologous to those of AMY1 and AMY2 [12].
• Both Amy1 and Amy2 activities were present in amniotic fluid from 14 weeks' gestation, and immunologic activity was present in pancreatic tissue sections from 15.9 weeks' gestation [13].
• The first secondary site in both AMY1 and AMY2 was only functional when substrate was bound in the active site [14].

Anatomical context of AMY1A

• A starch-coated slide assay was used to quantitate amylase activity in amniotic fluids, and samples with activity were studied by electrophoresis to determine the presence of salivary amylase (Amy1) and pancreatic amylase (Amy2) isozymes [13].
• Malaysians of Malay, Chinese, and Indian ancestries were electrophoretically phenotyped for Amy1 and saliva esterase region 1 (Set-1) from saliva, Amy2 from plasma, soluble and mitochondrial GOT and PGM3 from leukocyte and placenta [15].

Associations of AMY1A with chemical compounds

• To distinguish AMY1 transcripts from a mixture of AMY1 and AMY2, use was made of the differences in the ethidium bromide-stained agarose gel patterns obtained after digestion of the amplified exon 3-4 fragments with TaqI [16].
• Consequently, in the presence of this oligosaccharide substrate, acarbose bound both to the active site and to a secondary binding site. alpha-CD inhibited the AMY1 and AMY2 catalysed hydrolysis of amylose, but was a very weak inhibitor compared to acarbose.beta- and gamma-CD are not inhibitors [14].
• The hydrolysis of DP 4900-amylose, reduced (r) DP18-maltodextrin and maltoheptaose (catalysed by AMY1 and AMY2) was followed in the absence and in the presence of inhibitor [14].
• AMY-1 (associate of Myc-1) localization to the trans-Golgi network through interacting with BIG2, a guanine-nucleotide exchange factor for ADP-ribosylation factors [10].

Other interactions of AMY1A

• The human genes encoding salivary amylase (AMY1) and pancreatic amylase (AMY2) are nearly identical in structure and sequence [8].
• The long haplotype spans about 300 kb and contains six additional genes arranged in two repeats, each one consisting of two salivary amylase genes (AMY1A and AMY1B) and a pseudogene lacking the first three exons (AMYP1) [17].
• Salivary protein polymorphism was studied in 200 schoolboys, mainly Kisii and Luo from Kenya, East Africa. The frequencies of PR, PA, DB, PB and AMY1 genes were as follows: PR*1: 0.66, PA*(+): 0.18, DB*(+): 0.55, PB*2: 0.12, AMY1*A2: 0.008, AMY1*E: 0.03 [18].

Analytical, diagnostic and therapeutic context of AMY1A

• To explore the possible function of AMY-1, we have undertaken a search for interacting partners by co-immunoprecipitation experiments using cells stably expressing FLAG-tagged AMY-1 [10].
• Although variant bands of Amy1 V1N were detected by immunoblotting method using anti-human salivary amylase, those bands were not stained by starch-iodine method for the detection of amylase activity [19].

References