An inverse correlation between expression of a preprocathepsin B-related protein with cysteine-rich sequences and steroid 11beta -hydroxylase in adrenocortical cells.
A cDNA encoding a secretory protein hitherto unknown was cloned from mouse adrenocortical cells by subtractive hybridization between the cells without and with expressing steroid 11beta-hydroxylase (Cyp11b-1), a marker for the functional differentiation of cells in the zonae fasciculata reticularis (zFR). The deduced protein consisting of 466 amino acids contained a secretory signal, epidermal growth factor-like repeats, and a proteolytically inactive cathepsin B-related sequence. The amino acid sequence was 89% identical with that of human tubulointerstitial nephritis antigen-related protein. Among the mouse organs examined, adrenal glands prominently expressed its mRNA. The mRNA and its encoded protein were detected in the outer adrenocortical zones that do not express Cyp11b-1, i.e. the zona glomerulosa and the undifferentiated cell zone, while being undetectable in zFR that express Cyp11b-1. The new protein was designated as adrenocortical zonation factor 1 (AZ-1). Clonal lines with different levels of AZ-1 expression were established from Y-1 adrenocortical cells that originally express Cyp11b-1 but little AZ-1. Analyses of the clonal lines revealed that Cyp11b-1 is detected in the clonal lines maintaining little AZ-1 expression and becomes undetectable in those expressing AZ-1. On the other hand, irrespective of the AZ-1 expression, all clones expressed cholesterol side-chain cleavage enzyme, which occurs throughout the cortical zones. These results demonstrated that adrenocortical cells expressing AZ-1 do not express Cyp11b-1, whereas those with little AZ-1 express this zFR marker in vitro and in vivo, implying a putative role of AZ-1 in determining the zonal differentiation of adrenocortical cells.
Mukai
Kuniaki
K
Department of Biochemistry and Integrative Medical Biology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. mukaik@sc.itc.keio.ac.jp
Mitani
Fumiko
F
Nagasawa
Hideko
H
Suzuki
Reiko
R
Suzuki
Tsuneharu
T
Suematsu
Makoto
M
Ishimura
Yuzuru
Y
D000302:Adrenal Cortex / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins; D002403:Cathepsins / Q000096:biosynthesis* / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D003001:Cloning, Molecular; D003545:Cysteine; D004792:Enzyme Precursors / Q000096:biosynthesis* / Q000235:genetics; D054834:Lipocalins; D051379:Mice; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D013252:Steroid 11-beta-Hydroxylase / Q000096:biosynthesis*
D002352:Carrier Proteins; D004792:Enzyme Precursors; D054834:Lipocalins; D009363:Neoplasm Proteins; D011506:Proteins; C484283:Tinagl1 protein, mouse; D013252:Steroid 11-beta-Hydroxylase; D002403:Cathepsins; C057831:preprocathepsin B; D003545:Cysteine