Cell-type-specific and developmental regulation of heterogeneous nuclear ribonucleoprotein K mRNA in the rat nervous system.
Heterogeneous nuclear ribonucleoprotein K (hnRNP K) was originally identified as being part of the hnRNP particle. hnRNP K has subsequently been shown to be involved in a number of fundamental biological processes such as RNA transport and processing as well as transcription and translation. In addition, hnRNP K is an integral player in a variety of intracellular signal transduction pathways. Not surprisingly given this broad array of cellular functions, hnRNP K is a highly interactive protein binding directly to both single- and double-stranded nucleic acids as well as numerous signaling proteins. Interestingly, earlier studies demonstrated that hnRNP K protein is not ubiquitously expressed and does not exist in a fixed stoichiometry with other hnRNP proteins. We have extended this earlier work and report here the spatially- and developmentally-regulated expression of hnRNP K mRNA during development of the rat nervous system. In the central nervous system, hnRNP K mRNA expression gradually decreases during development until it is restricted to a very limited number of structures including most notably the hippocampus and the retina. Immunohistochemical data indicate that hnRNP K protein expression closely parallels hnRNP K mRNA expression. In contrast to the central nervous system, hnRNP K in the peripheral nervous system remains high throughout embryonic development with dramatic expression in several peripheral ganglia.
Department of Molecular Medicine, University of Texas Health Science Center, San Antonio, TX 78245, USA.
Adam R
AR
Blanchette
Yuly F
YF
Fuentes Medel
Paul D
PD
Gardner
D000818:Animals; D002490:Central Nervous System / Q000196:embryology* / Q000378:metabolism*; D005260:Female; D034641:Heterogeneous-Nuclear Ribonucleoprotein K / Q000235:genetics* / Q000378:metabolism; D006624:Hippocampus / Q000196:embryology / Q000378:metabolism; D007150:Immunohistochemistry; D009928:Organ Specificity; D017933:Peripheral Nervous System / Q000196:embryology / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000196:embryology / Q000378:metabolism
D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D012333:RNA, Messenger