What are the "mammalian vectors N1 and C1"? - (Jan/27/2013 )

I'm still new in my research lab, and I've realized that a lot of the plasmids that I use are in N1 or C1. (e.g. pRSETa in N1, PAmCherry1 in C1) When my PI says they're "mammalian," does she mean that these circular plasmids readily exist in human cells? If so, how/why do we use them? If not, how and from where have these N1 and C1 been isolated? Also, do the N and the C have to do anything with the amino and carboxyl termini of amino acid chains?

I really need some help.
Thank you!

N and C are, as you thought the N-terminal and C-terminal tags, often it is a bit counter-intuitive for these though, for example in the pEGFP-C1 plasmid, if you clone into this, the GFP will be N-terminal to the insert (i.e. the cloning site if C-terminal, hence the C).

These plasmids may be able to persist in the cell, but it will depend on the sequence and the cell type as to whether they have the correct bits of information for this to happen.

Usually a "mammalian" vector has a promoter (e.g. viral promoter, mouse promoter) that works in eukaryotic cells, as opposed to a bacterial promoter which won't. Eukaryotic promoters will often also work in bacterial cells, but not necessarily and often not very efficiently.